Islamic State militants have dug trenches around natural gas and hydrogen tanks at Iraq’s largest refinery, raising the stakes in a battle where the price of victory may be the refinery itself.
The Baiji refinery remains contested despite more than 300 coalition air strikes in the vicinity since the Islamist insurgents overran the area last June.
The militants launched their fiercest attack on the installation last month and now control large parts of the complex in which 200 Iraqi security forces are trapped.
The Pentagon last week said the outcome of the battle — in which Iraqi security forces backed by coalition warplanes are fighting to retake the refinery from Islamic State militants — could not be predicted but warned it was going in “the wrong direction”.
Islamic State appears to have committed itself to an all-out fight there, proving it can still seize the initiative after being ejected from the city of Tikrit further south in early April, military officials and experts say…