BAGHDAD: ISIS suicide bombers and fighters attacked the center of Iraq’s northern oil refinery town of Beiji overnight, forcing the army and Shiite fighters to pull back, military sources and the local mayor said Sunday. The town of Beiji and its refinery – Iraq’s largest – have been a battlefront for more than a year. The latest ISIS offensive comes after authorities said they controlled nearly the whole town and expected to drive insurgents from the refinery within days.

The militants attacked around 8 p.m. Saturday with two suicide car bombings. The blasts were followed by fierce clashes that lasted until midnight and drove the army and paramilitaries from the center of town, two army colonels said.

Separately, officials said bombings targeting Shiite districts killed 15 people in and around Baghdad.

Police officials say a bomb exploded Sunday night near a cafe in the Shiite district of al-Obeidi on the eastern edge of Baghdad, killing four people and wounding 14 others.

Another evening bomb blast near a small restaurant killed four people and wounded 11 others in the southeastern suburb of Jisr Diyala.

Earlier, a bomb went off at a bus stop in the northeastern suburbs of the capital, killing four people and wounding nine. Another bombing near a bus stop killed three people in Baghdad’s northwestern district of Shulla.