Islamic State insurgents battled Iraqi forces in the center of Baiji on Tuesday, a week after the army broke their prolonged siege of the country’s largest oil refinery just outside the town, an army officer and residents said.

The renewed fighting in Baiji by the Islamist militants, who control thousands of square miles of territory in Iraq and Syria, appeared aimed at reimposing that stranglehold around the sprawling oil facility 2 miles (4 km) to the north.

Islamic State (IS) fighters were present in four of Baiji’s 12 neighborhoods, as well as areas on the perimeter of the sprawling refinery complex. But the army controlled its southern approaches, preventing insurgents from surrounding it, according to a Baiji resident who toured the area. […]