WASHINGTON: The United States has begun using attack helicopters to target the Islamic State group in Libya, a defence official said on Tuesday. American jets have, since the start of August, been helping fighters loyal to the Government of National Accord (GNA) retake the coastal city of Sirte – conducting dozens of strikes on IS fighting positions and equipment. Lieutenant Commander Anthony Falvo, a spokesman for the US military’s Africa Command said Marine Corps AH-1W Super Cobra attack helicopters had in recent days joined the operation. “The Cobras provide additional precision air strike capability,” said Falvo, “It gives us a little bit more flexibility.” Super Cobra gunships are based on the USS Wasp – an amphibious assault ship in the Mediterranean. Harrier jets are also being launched to conduct strikes on Sirte. As of Monday, the United States had conducted 77 air strikes in the city. Pro-GNA forces, backed since August 1 by US air strikes, began an assault in mid-May to expel IS from what had been its Sirte stronghold.