IRBIL, Iraq — A top Iraqi commander told The Associated Press that the operation to retake the city of Mosul from the Islamic State group could be complete in three months or less.

“It’s possible” that Mosul will be liberated in in that time frame, Lt. Gen. Talib Shaghati said in an interview with the AP on Tuesday evening. However, he warned it is difficult to give an accurate estimate of how long the operation will take because it is not a conventional fight.

“There are many variables,” he said, describing the combat as “guerrilla warfare.”

On Wednesday, Iraqi forces announced that three more neighborhoods in eastern Mosul had been retaken from IS fighters. Brig. Gen. Haider Fadhil of Iraq’s special forces estimated about 85 percent of eastern Mosul was now under Iraqi control.

The massive offensive involving some 30,000 Iraqi forces was launched in October and Iraqi leaders originally pledged the city would be retaken before 2017. However as the fight enters its fourth month, only about a third of the city is under government control.

Iraqi forces — largely led by special forces — have slowly advanced across Mosul’s east. Fierce IS counterattacks have killed and injured hundreds of Iraqi troops and inflicted considerable damage to Iraqi military equipment. Repeatedly, after what appeared to be swift progress on the ground, Iraqi forces have been pushed back by IS counterattacks overnight.

However, Shaghati said the counterattacks — specifically car bombings — have slowed. He estimated his forces are seeing less than half the number of IS car bomb attacks on the front than they were faced with when the operation first began.

The U.S.-led coalition bombed the bridges spanning the Tigris river connecting Mosul’s east and west in November in an effort to stop the flow of car bombs to Iraqi frontline positions in the eastern half of the city.

Shaghati, the top commander of Iraq’s special forces and the Commander of Iraq’s Joint Military Operation said that while many forces are participating in the Mosul fight, Iraq’s special forces are the only troops with the skills to fight IS.