Pentagon officials say U.S. investigators have visited Benghazi in eastern Libya for the first time since an attack on the city's American consulate killed the U.S. ambassador to the country last month.
Defense Department spokesman George Little said a Federal Bureau of Investigation team spent several hours in Benghazi on Thursday, accompanied by U.S. troops who provided transportation and security.
Libyan security officials said the FBI team inspected the damaged U.S. consulate building and collected evidence. They said the road leading to the compound was sealed off by Libyan military vehicles mounted with weapons.
Militants set fire to the Benghazi consulate and fired on a nearby U.S. safe house on September 11, killing U.S. Ambassador Chris Stevens and three other Americans, including a State Department computer expert and two former Navy commandos. The U.S. and Libyan governments say the incident was a terrorist attack.
It remains unclear why U.S. investigators did not visit Benghazi earlier. The Pentagon spokesman told reporters that since the attack, the Obama administration has been "chasing leads in various ways," not "sitting around waiting for information" to come in.
Little declined to provide details of security arrangements for the FBI team's visit, saying the U.S. military "may have to do this again."
U.S. Secretary of State Hillary Clinton said Wednesday the United States will not rest until it determines how the Benghazi attack happened and tracks down the perpetrators.
The Obama administration initially described the incident as a spontaneous Libyan protest against an American-made anti-Islam film, which had sparked Islamist demonstrations in Cairo earlier that day. It later acknowledged that suspected terrorists may have planned the Benghazi assault.
U.S. Republican lawmakers have accused the Obama administration of misleading the public and not doing enough to protect the Benghazi mission before the attack.