WASHINGTON U.S. authorities are investigating possible collusion between militants who launched a deadly attack on the U.S. consulate in Benghazi, Libya and locally hired Libyan personnel guarding the facility, three U.S. officials said.
So far there is no proof that the attackers, who killed U.S. Ambassador Christopher Stevens and three other U.S. officials, were helped by Libyan security personnel hired by the consulate. One official said the Obama administration was playing down this possibility.
However, all the officials said that the question of whether the attackers had inside help or advice was a serious issue in the U.S. investigation into the attack, which occurred on the 11th anniversary of the September 11, 2001 attacks on the United States.
Officials discussed the inquiry, still in its initial stages, only on condition of anonymity.
A team of FBI investigators has gone to Libya to lead the investigation.
The question of whether the Benghazi attackers could have been helped by locally hired guards was raised during a hearing on Wednesday by the Senate Committee on Homeland Security.
The panel's top Republican, Senator Susan Collins, asked Matthew Olsen, director of the National Counterterrorism Center, whether there were indications of communications between militants and the Libyan guards prior to the attack.
Olsen said this was an issue "better addressed" in closed briefings that Secretary of State Hillary Clinton and National Intelligence Director James Clapper were scheduled to give to Congress on Thursday afternoon.
One possible indication of suspicious activity on the part of Libyan guards at the consulate is a cryptic message which Sean Smith, an American diplomat killed in the Benghazi attack, sent to friends in the online gaming community, in which he was a long-time participant.
A gaming website called The Mittani on September 12 posted what it said was a message Smith sent before his death. In the message, a person using the screen-name "Vile_rat", which The Mittani said was Smith's, the writer said: "assuming we don't die tonight. We saw one of our 'police' that guard the compound taking pictures."
U.S. officials familiar with investigations into the attack had no immediate comment on Smith's purported message.
The State Department has said Blue Mountain Group, a private security company based in Carmarthen, Wales, had a contract related to vetting and hiring local residents to perform security tasks at the Benghazi consulate.
A government contracting database shows the department signed a contract of this nature last May for $387,000, with options raising the value to $783,000. The database entry, which does not name Blue Mountain Group, describes the work the contractor was supposed to do as "Local Guard Program - Benghazi."
Blue Mountain Group's Internet homepage describes it as a security company whose personnel had "many years" service in British special forces, including the Britain's two most elite commando units, the Special Air Service and Special Boat Service.
A person who answered the phone at Blue Mountain Group's offices declined to comment.
British authorities shut their consulate in Benghazi earlier this year after a convoy carrying the British ambassador was attacked by militants with a rocket-propelled grenade. Two bodyguards were injured but Ambassador Dominic Asquith escaped unhurt. British authorities have said that violent Islamic factions are more prevalent in Benghazi and its surrounding area than other parts of Libya.
One group that has been linked to the attack is Ansar al Sharia, or Supporters of Sharia. U.S. officials acknowledged this week that a leader of that militant faction is a former inmate of the U.S. detention facility at Guantanamo Bay, Cuba.
The officials told Reuters that the militant leader, known as Abu Sufian Ibrahim Ahmed bin Qumu, was released from Guantanamo in 2007 by President George W. Bush's administration.
The officials said that it was unclear whether Qumu participated in or helped to direct the Benghazi attack. At least one purported Ansar al Sharia spokesman has denied the group's involvement in the violence.
(Additional reporting by Andrew Quinn and Warren Strobel; Editing by Claudia Parsons)