A spokesman has described claims that the attacks were the result of a 'continuing security breach' and diplomats should have been warned before the attacks as 'completely wrong.'
British newspaper The Independent had claimed that the State Department had credible information warning of attacks on embassies 48 hours before mobs stormed the outposts in Libya and Cairo.
However, a spokesman told Politico: 'This is absolutely wrong. We are not aware of any actionable intelligence indicating that an attack on the U.S. Mission in Benghazi was planned or imminent.'
Diplomats had long been on their guard in Benghazi, a city that was the cradle of Libya's Western-backed revolution but also home to Islamists who have attacked foreign envoys.
Yet a long night of mayhem in which the U.S. consulate was overrun and torched, the ambassador lost and dying alone in the smoke while rescuers ran into a deadly ambush as they sought to save survivors, seemed to overwhelm U.S. security procedures.
Killed in the attack were U.S. Ambassador Chris Stevens, information management officer Sean Smith, and private security guards Glen Doherty and Tyrone S. Woods.
Libyan authorities said four people were arrested at their homes Thursday, but he refused to give any further details.
He said it was too early to say if the suspects belonged to a particular group or what their motive was. Libya's new prime minister, Mustafa Abu-Shakour, said authorities were looking for more suspects.
Accounts from Libyan and U.S. officials, and from locals who watched what began as a protest on Tuesday against a crudely made American film that insults the Prophet Mohammad spiral into violence and a military-style assault on U.S. troops, point to a series of unfortunate choices amid the confusion and fear.
The actions of Libyan former rebel fighters assigned to help guard the lightly fortified compound may also face scrutiny. Libyan officers suggested that sympathy for the popular anger at the slight to their religion, as well as simple fear under heavy fire, meant the guards may have done little to defend the walls.
Much remains unknown, notably the extent to which armed militants may have prepared in advance for an attack as opposed to merely profiting from the opportunity of an angry crowd spinning out of control in a country where guns are everywhere.
However, this much is clear: a crowd gathered at dusk, about 7 p.m. (1700 GMT), chanting slogans against the film and angry at Washington's failure to act against its promoters. At some point, shooting began, with some in the crowd thinking they were under fire from the consulate. Around 10 p.m., rioters surged into the compound, bullets and grenades flew, and fires started.
Among the assailants, Libyans identified units of a heavily armed local Islamist group, Ansar al-Sharia, which sympathizes with al Qaeda and derides Libya's U.S.-backed bid for democracy.
Eventually, some three dozen Americans drove off to a safe house, knowing one diplomat was dead and Ambassador Christopher Stevens missing. When an eight-man rescue team flew in from Tripoli, they and their Libyan escorts were pinned down with the survivors by another attack in which two more Americans died.
Meanwhile, Stevens, 52, had been found by local people and taken, unrecognized, to a hospital, around 1 a.m. A doctor failed to revive him and pronounced him dead of smoke inhalation.
Around dawn, at 7 a.m., the beleaguered American survivors, with their battered military rescue party, were finally escorted back to Benghazi airport by a convoy of Libyan militia fighters in dozens of vehicles, to be flown to Tripoli and safety.
The fact that the attack took place on the 11th anniversary of al Qaeda's September 11 attacks on the United States, and that the ambassador, normally based in the capital Tripoli, was present in person, has prompted speculation that it may have be elaborately planned in advance by the likes of Ansar al-Sharia.
Three months ago to the day, the British ambassador survived a rocket attack as his convoy approached London's Benghazi consulate and there has been other violence against foreigners, mostly blamed on anti-Western Islamists, with some possible involvement by angry loyalists of the late Muammar Gaddafi.
Diplomats say foreign staffing in Benghazi has generally been kept low to reduce the security risks. But the city is home to key oil installations, Libya's economic mainstay, and a local source said Stevens had been expected at meetings with state oil executives on Wednesday, explaining at least part of his visit.
Some of those who took part in the initial demonstration in Benghazi insisted it was a spontaneous, unplanned public protest which had begun relatively peacefully. Anger over the film also saw an unruly protest at the U.S. embassy across the Egyptian border in Cairo on Tuesday evening, with protesters scaling the walls.
Local journalists also saw an eclectic gathering of people infuriated by religious sentiment but few of them bearing arms and most not appearing affiliated with hardline Islamist groups.
"When we had heard that there was a film that was insulting to the Prophet, we, as members of the public, and not as militia brigades, we came to the consulate here to protest and hold a small demonstration," said a 17-year-old student named Hamam, who spoke to Reuters at the devastated compound on Wednesday.
By his account, while some demonstrators fired rifles in the air - a far from uncommon sight in postwar Libya - a rumor spread that a protester had been wounded by firing from inside the consulate and Hamam and many others went off to retrieve guns which, like many Libyans, they keep at home for security.
"So we started shooting at them," Hamam said. "And then some other people also threw homemade bombs over the fences and started fires in the buildings. There was some Libyan security for the embassy, but when the bombs went off they ran off."
Abdel-Salam al-Bargathi, who runs the security operations of the former rebel February 17 Brigade, which effectively forms the police force for Benghazi while the new authorities work to establish new institutions, said he heard explosions start around 8:30 p.m. from his headquarters a mile or so away.
"There was a lot of chaos and confusion when the clashes began," he said. By 9 p.m., he was receiving calls from his units at the scene that rocket-propelled grenades were being fired at the consulate. A power cut had plunged the area into darkness.
"People started running into each other and nobody knew who was who," Bargathi told Reuters, saying that around this time he began ordering preparations to be made for an evacuation.
Tellingly, he and another senior officer, Wissam Buhmeid, the commander of the pro-government local defense force, the Libya's Shield Brigade, stressed that the Libyan guards on the consulate - estimated by Bargathi at up to 40 or more - may have felt little will to defend the compound from what they, and many other Libyans, judged to be justified religious indignation.
"I first of all place the blame on the United States itself for allowing such a movie to be produced. This was the product of the anger of Muslims," Buhmeid said, noting also that the guards had only light weapons in the face of rockets.
"I saw utter chaos. The power went out and it was completely dark," he said. "There were definitely people from the security forces who let the attack happen because they were themselves offended by the film; they would absolutely put their loyalty to the Prophet over the consulate. The deaths and injuries and attacks are all nothing compared to insulting the Prophet."
Bargathi, of the police command, said the killings had taken the protest too far, but said: "What we saw was a very natural reaction to the insult to the Prophet. We condemn the deaths but the insult to the Prophet made people very angry."
Ali Fetori, 59, an accountant who lives near the embassy, said: "The security people ... just all ran away and the people in charge were the young men with guns and bombs."
U.S. officials said the consulate's perimeter was breached 15 minutes after the crowd tried to storm in at around 10 p.m. The main villa was set on fire, with three Americans inside - the ambassador, IT specialist Sean Smith and a security officer.
"They became separated from each other due to the heavy dark smoke while they were trying to evacuate the burning building," one senior official said. The security officer made it outside.
"They found Sean. He was already dead. And they pulled him from the building. They were unable, however, to locate Chris, before they were driven from the building, due to the heavy fire and smoke and the continuing small arms fire."
Ali Khamis, a gardener, said he was in his room at the consulate when the attack happened. "They came into the compound, through all the gates. They were shouting 'Allahu akbar' and they were shooting in the air when they came in," he said.
Hamam, the young protester, said he had seen an American "totally covered in soot and black" lying apparently dead in the compound. Some people he said were chanting, "Allahu akbar (God is great), We are victorious over the infidels."
Photographs published on the Internet appeared to show Stevens unconscious and begrimed, being held by local men.
Ziad Abu Zaid, who was the duty doctor in the emergency room at Benghazi Medical Centre, said local civilians had brought in a man they said was American around 1 a.m. "He came in a state of cardiac arrest," Abu Zaid said. "I performed CPR for 45 minutes, but he died of asphyxiation due to smoke inhalation."
Only when someone told him the patient had come from the consulate did he make out Stevens's locally well-known features beneath the smoke and grime that obscured his face, he said.
Libyan officials said the surviving Americans withdrew to a safe house. It would be normal security procedure in countries like Libya for international personnel to have a secure, secret location prepared for just such an eventuality.
Captain Fathi al-Obeidi, commander of a special operations force for the February 17 Brigade, told Reuters that he took a call about 1:30 a.m. from Tripoli telling him that a helicopter was on its way from the capital's Mitiga airport with a rescue squad of eight U.S. troops - he described them as marines.
After he met them at Benghazi airport with a convoy of 10 vehicles, mostly pickup trucks, one mounted with an anti-aircraft cannon, the U.S. force directed Obeidi and his men to the GPS coordinates of a farmhouse to find the survivors there.
Here, two more things went wrong. First, Obeidi found four times as many Americans at the single-storey, fortified house as he had been told expect - 37, not just 10. So he did not have enough transport. Then, the villa came under massive attack.
This time, there was little doubt in the minds of Libyans who experienced it that this was a well-organized assault by men who had mastered the complexities of military mortar fire.
"This attack was planned," Obeid said. "The accuracy with which the mortars hit us was too good for any ordinary revolutionaries."
While some Libyan officials suggested that former soldiers from Gaddafi's army may have been involved in Benghazi, some of the Islamist fighters also have substantial military experience from years spent fighting with the Taliban in Afghanistan.
Though Libya's deputy interior minister described the locating of the safe house as a "critical security breach," the attack may not have been planned for long in advance. The assailants would have had some hours to follow the fleeing Americans and set up an ambush after the consulate attack.
"It began to rain down on us," Obeidi said just as the rescue force was preparing to leave. "About six mortars fell directly on the path to the villa," he said.
One American fell wounded by him. A mortar struck the building itself, throwing from the roof another American posted there onto the men below.
"I was being bombarded by calls from all over the country by Libyan government officials who wanted me to hurry and get them out," he said. "But ... I needed more men and more cars'.
Two Americans, including one of the eight security personnel sent from Tripoli, were killed and several wounded.
Finally, dozens more vehicles from the Libyan security forces arrived, the attackers melted away and, as the sun came up over the desert, they reached Benghazi airport, from where the surviving Americans and the bodies were flown out.
Following the deadly attacks in Libya, investigators are looking into whether a mole gained access to sensitive information, helping Libyan extremists in their deadly attack Tuesday night.
A high-ranking Libyan official then insinuated that the spy tipped off the rebels, sending them to the nearby safe house, where two more Americans were killed and one injured in the melee.
Eastern Libya's deputy interior minister, Wanis el-Sharef, said a mob first stormed the consulate Tuesday night and then, hours later, raided a safe house in the compound just as U.S. and Libyan security arrived to evacuate the staff.
That suggested, el-Sharef said, that infiltrators within the security forces may have tipped off the militants to the safe house's location.
Documents containing delicate information have been lost in the attack, the Independent. These documents are believed to contain the names of Libyans who are also working for Americans, as well as information on oil contracts.
It is also believed that the attacks could be retribution for a drone strike which killed a top al-Qaeda official in Pakistan, who was said to be Libyan.
One security guard told how he was hit by a grenade in the attack and then, a he was lying on the ground, bleeding and in excruciating pain when a bearded gunman came down the wall and shot him twice in the right leg, screaming: 'You infidel, you are defending infidels!'
'Later, someone asked me who I was. I said I was the gardener and then I passed out. I woke up in hospital,' said the guard, who spoke to The Associated Press from his bed at a Benghazi hospital.
The witness account came as protests of the mysterious film, Innocence of Muslims, continued in the Middle East.
An angry throng broke into the U.S. Embassy in Yemen, and clashes between security forces and demonstrators near the fortress-like embassy compound in the heart of Cairo left nearly 200 people injured and two police trucks burned.
Speaking at his Benghazi office, el-Sharef, who was running the Interior Ministry's operations room commanding security forces in the city during the attack, gave the most detailed account to date to come out of Libya of what happened the night of the attack. His version, however, leaves some questions unanswered and does not provide a definitive explanation on the motives behind the attack and the identity of the perpetrators.
Meanwhile, top officials warned Thursday that the violence which has engulfed the Middle East following the release of a film mocking the Prophet Mohammed could spread to the U.S.
The Joint Intelligence Bulletin suggested that as well as widespread protests, the furore could be used by extremists to radicalise American Muslims.
The report, issued by the FBI and the Department of Homeland Security, follows three days of angry demonstrations in Muslim countries directed at U.S. embassies, which led to the killing of the American ambassador to Libya on Tuesday night.
The report warned that 'the risk of violence could increase both at home and abroad as the film continues to gain attention', according to ABC News.
It continued: 'First responders should remain aware of the potential for spontaneous large crowds and protests that could overwhelm resources and should be vigilant for possible efforts to encourage peaceful protesters to commit acts of violence.'
Officials were particularly cautious about the risk of Islamic radicals exploiting the outrage over the film to engineer attacks against mainstream society and other faiths.
They suggested that 'violent extremist groups in the United States could exploit anger over the film to advance their recruitment efforts', and asked religious bodies to prevent 'plotting against Jewish, Coptic, Islamic, or any other faith-based communities'.
The bulletin comes as the rising anger provoked by the film has seen protestors storm U.S. embassies in Muslim countries from Egypt to Yemen, where four people have been killed and dozens others injured.
Chanting 'death to America', hundreds of protestors marched on the U.S. Embassy compound in Yemen's capital today, where they burned the American flag, used stones to smash windows, and set fire to cars, before breaking through the main gate of the heavily fortified compound in eastern Sana'a.
Security has been ramped up at U.S. embassies and consulates around the world, and at least one cemetery for American veterans, while President Obama called the leaders of Libya and Egypt to continue helping him to ensure the safety of diplomatic personnel.
One of those killed in Benghazi alongside U.S. Ambassador Christopher Stevens was 42-year-old Glen Doherty, a family friend told CBS Boston today.
Libyan authorities have made four arrests in the investigation into the attack on the U.S. consulate in Benghazi in which the U.S. ambassador and three embassy staff were killed, the deputy interior minister said on Thursday.
'Four men are in custody and we are interrogating them because they are suspected of helping instigate the events at the U.S. consulate,' Wanis Sharif told Reuters.
He gave no more details.
There were protests in Tunisia, Sudan and Morocco overnight, and the demonstrations have reached Cairo and Baghdad.
On Thursday, riot police in Indonesia were standing guard outside the U.S. Ambassador's Jakarta residence in anticipation of further action.
Once inside the compound in Sana'a, Yemeni protestors brought down the U.S. flag, burned it and replaced it with a black banner bearing Islam's declaration of faith - 'There is no God but Allah.'
CNN reported that four people were killed in the clashes, and dozens of other security officials and protesters were injured.
Before storming the grounds, demonstrators removed the embassy's sign on the outer wall, set tires ablaze and pelted the compound with rocks.
Yemeni security forces who rushed to the scene fired in the air and used tear gas to disperse the demonstrators and were eventually able to drive them out of the compound. It was not immediately clear whether anyone was inside the embassy at the time of the attack.
Some protestors held aloft banners declaring 'Allah is Greatest'. Tires blazed outside the compound and protesters scaled the walls.
'We can see a fire inside the compound and security forces are firing in the air. The demonstrators are fleeing and then charging back,' one witness said.
It was similar to an attack on the US Embassy in the Egyptian capital of Cairo on Tuesday night.
Witnesses said there were some injuries on both sides but gave no exact figures.
Yemen, a key U.S. ally, is home of al Qaeda in the Arabian Peninsula (AQAP), which is viewed by Washington as the most dangerous branch of the militant network established by Osama bin Laden.
Yemen is fighting an al Qaeda-backed insurrection largely in the south of the country. Its embassy in Washington did not report any casualties.
An embassy statement said Yemen's government condemned the attack by protesters angry at a film seen as insulting to Islam, adding security forces had restored order at the complex.
TIMELINE OF TERROR: WHAT AUTHORITIES BELIEVE HAPPENED DURING THE LATE-NIGHT CONSULATE RAID
Well-armed Libyan extremists launched a sustained attack on the U.S. Consulate in Benghazi, Libya, on Tuesday, killing four State Department employees, including the American ambassador to Libya Chris Stevens and foreign service officer Sean Smith, and wounding three others.
The consulate, like all other U.S. diplomatic missions around the world, conducted a pre-9/11 anniversary security check. It found no imminent threat and therefore no need to boost security around the anniversary, according to senior U.S. officials, who spoke on condition of anonymity because the reporting of the incident is still preliminary.
The consulate consists of a main building and a nearby annex, each of which are protected by local Libyan guard force, a physical perimeter barrier and a ‘robust’ American security presence inside the compounds. All times are local Benghazi time, and accounts are from officials
10:00pm Tuesday - The main consulate building begins began taking fire from unknown Libyan extremists. There are about 25 to 30 employees in the consulate and the annex at the time of the attack.
10:15 pm - Attackers gain access to main consulate building and set compound on fire. In the ensuring chaos, many escape the building, but Stevens, Smith and a regional security officer remain inside. They become separated due to heavy smoke and confusion while trying to evacuate. The security officer makes it outside and he and others from the consulate and annex go back into the building to try to rescue Stevens and Smith. They find Smith dead and pull him out but are forced by the flames, smoke and gunfire to withdraw before they can locate Stevens.
10:45pm - A group of security officers from the annex try to take the consulate building back from the attackers, but they are repelled. Everyone rescued is brought to the annex.
Midnight - The annex comes under heavy fire from the attackers. The shooting lasts more than two hours during which the other two Americans are killed and two Americans are wounded.
2:30an Wednesday - Libyan and U.S. security forces retake the annex. Officials believe that Stevens got out or was pulled out of the main consulate building during the battle for the annex and was taken to the hospital. The officials do not know if Stevens was alive when he arrived at the hospital.
6:00am - U.S. officials are told that Stevens is dead but are not able to confirm it immediately because they have not seen the body. The body is returned to U.S. personnel at the Benghazi airport at dawn.
Read more: dailymail
