Police and interior ministry forces will enter Mosul to help the army defeat the Islamic State group in the east of the city, Iraqi commanders said on Saturday.

Lieutenant General Raed Shaker Jawdat said federal police forces and the elite Rapid Response forces from the interior ministry would soon move in to assist the army's 9th Armoured Division.

The move comes three days after jihadists ambushed the army in the Al-Salam hospital in southeast Mosul, killing several soldiers and forcing them to pull back.

"Our units moved towards Hamdaniyah to support the 9th Division, exact revenge on Daesh for what they did at Al-Salam hospital and retake areas on the east bank of the Mosul," Jawdat told AFP, using an Arabic acronym for IS.

Hamdaniyah, also known as Qaraqosh, is a large town southeast of Mosul which was retaken before Iraqi forces first entered Mosul last month and is used as a staging base for some of the forces operating in the area.

Lieutenant General Qassem al-Maliki, the commander of the 9th Division, said he lost 13 men in the fighting around the hospital. IS and some other security sources gave higher tolls.

Maliki told AFP that Rapid Response forces were also poised to enter the city on the eastern side to support the 9th Division.

The federal police and interior ministry forces have so far mostly been fighting along a southern front which has stalled within striking distance of Mosul airport, which lies on the western bank of the Tigris river that divides the city.

Most of the fighting in Mosul has been done by the elite Counter-Terrorism Service, which has entered Mosul from the east and has retaken several neighbourhoods.

All commanders have said however that the jihadists have offered stiffer resistance than expected in the city, prompting fears that the operation launched on October 17 to retake IS's last major Iraqi bastion could drag on.