Up to 100,000 children are in danger as Iraqi forces battle to retake west Mosul from the Islamic State jihadist group, the United Nations children's agency Unicef said yesterday.

Nearly eight months into the massive operation to recapture Iraq's second city, security forces have retaken all but a handful of areas in west Mosul from the jihadists.

But those areas - Mosul's Old City and others nearby -are still home to large numbers of civilians in grave danger from the fighting as well as from a lack of food, medicine and clean water.

"An estimated 100,000 girls and boys remain in extremely dangerous conditions in the Old City and other areas of west Mosul. Many are caught in the crossfire, and hospitals and other medical facilities have reportedly come under attack," Unicef said in a statement.

"As the fighting continues, Unicef calls on all parties in west Mosul to protect children and keep them out of harm's way at all times, in line with their obligations under humanitarian law," it said.

Unicef said it has received reports of civilians including children being killed in west Mosul, some of them as they sought to flee.

The Mosul operation has taken a heavy toll on civilians, pushing more than 750,000 to flee their homes and leaving hundreds dead or wounded.