An Iraqi soldier rides in an armoured vehicle in Salahuddin province, March 4, 2015. Islamic State militants have set fire to oil wells in the Ajil field east of the city of Tikrit to try to hinder aerial attacks aimed at driving them from the oilfield, a witness and military source said. A police source in Salahuddin province, where Tikrit is located, said an eight-vehicle convoy of Islamic State insurgents attacked Iraqi forces at dawn on Thursday in al-Muaibidi area east of Alam. Picture taken March 4, 2015. REUTERS/ Mahmoud Raouf ( IRAQ - Tags: CIVIL UNREST MILITARY CONFLICT POLITICS)