Tripoli: Libyan authorities have reportedly arrested several people in connection with the attack on the US envoy and three other American officials in Benghazi.
Libyan officials said that those arrested are being interrogated on suspicion of having instigated the attack.
According to the BBC, new Libyan Prime Minister Mustafa Abu Shaqur said that the investigation was making progress.
The attack took place on Tuesday night during protests over a US-made film that mocks Prophet Mohammed.
Similar protests have spread across the Middle East and North Africa.
Four US embassy staff died in the clashes in Benghazi, including Ambassador Chris Stevens.
Meanwhile, US President Barack Obama has promised to do whatever is necessary to protect US citizens abroad and said he was urging foreign governments to guarantee their security.