A U.S. defense contractor was killed and several American and Iraqi troops were wounded Friday after roughly 30 rockets were fired at the Iraqi military compound near Kirkuk, U.S. officials said. The exact number of troops injured in the attack was not immediately disclosed, nor was the severity of the injuries. Col. Myles Caggins, spokesman for the U.S.-led coalition fighting the Islamic State in Iraq, said Iraqi security forces were taking the lead in investigating and responding to the attack. Protests in Iraq have left more than 450 people dead since October, most of whom were killed by security forces. Under mounting pressure, Prime Minister Adel Abdul-Mahdi resigned last month in response to the mass demonstrations.