"Islamic State of Iraq and the Levant" (ISIL) fighters are using small commercial drones to attack Iraqi security forces, as the group keeps losing more ground in the battle for Mosul, officials said Wednesday (January 11th).

Col. Brett Sylvia, who commands an "advise and assist" US unit in Iraq, said ISIL fighters are attaching small munitions to quadcopters in an attempt to kill local forces as they retake Mosul.

"They are small drones with small munitions that they have been dropping," Sylvia said.

While the munitions were no larger than "a small little grenade", he said, that was enough to do what "ISIL does, and that is just, you know, indiscriminate killing", he said.

The group's use of small drones is not new, Sylvia said, though initially they were mainly used for reconnaissance.

"They are (now) using them to drop munitions as Iraqi forces push into Mosul," he said.

Iraqi forces on Thursday liberated two new neighbourhoods in eastern Mosul, Ninawa operation commander Lt. Gen. Abdul Ameer Rashid Yarallah said in a statement.

"Joint Iraqi forces have liberated Somar and al-Saherun neighbourhoods and have raised the Iraqi flag on them," he said, noting that with this new success, Iraqi forces have retaken most of the eastern side of Mosul.

On Mosul's western front, the Iraqi air force killed a senior ISIL leader Thursday in an airstrike that targeted one of the group's sites in al-Aamel neighbourhood, the Iraqi Ministry of Defence said.

Another airstrike launched Wednesday night destroyed an ISIL camp at the Badoosh cement plant that the group was using as a headquarters, the ministry said in a statement.