The US intelligence community said that attack on a US consulate in Libya was by militants linked to al-Qaeda, but noted that "many unanswered questions" remained.

The US intelligence community said that attack on a US consulate in Libya was by militants linked to al-Qaeda, but noted that "many unanswered questions" remained.

"It remains unclear if any group or person exercised overall command and control of the attack, and if extremist group leaders directed their members to participate," Shawn Turner, spokesman for the Office of the Director of National Intelligence, said in a statement Friday.

"We do assess that some of those involved were linked to groups affiliated with, or sympathetic to Al-Qaeda."
US Ambassador to Libya Christopher Stevens and three other Americans were killed in the assault.

"As we learned more about the attack, we revised our initial assessment to reflect new information indicating that it was a deliberate and organized terrorist attack carried out by extremists," Turner explained.

But Turner stressed that despite "progress" made in the investigation, "there remain many unanswered questions."