Iraqi troops backed by helicopter gunships regained ground in the northern town of Sulaiman Pek,160 km (100 miles) north of Baghdad, on Friday.

Iraqi troops backed by helicopter gunships regained ground in the northern town of Sulaiman Pek,160 km (100 miles) north of Baghdad, on Friday, the mayor said.

At least 12 people were killed by the army, according to the town's mayor, Talib Mohammad, who identified them as members of the so-called 'Islamic State in Iraq and the Levant' (ISIL).

"The army is making good progress in the town," he said. "We have to admit it's not an easy job as snipers and roadside bombs planted by militants are forcing military forces to be slow and vigilant."

The ISIL have been regaining ground in Iraq over the past year, particularly in the western province of Anbar, where gunmen opposed to the country's government took over the city of Falluja last month.

The Iraqi army has surrounded Falluja and threatened a ground assault to retake it unless the ISIL militiamen lay down their arms by Friday.

Police forces are in control of government buildings, the mayor said, despite repeated attempts by the militants to break into them, the mayor said.

"Military forces backed by helicopters are controlling now around 70 percent of the town and the gunmen started to leave their positions," Mohammad said.