A displaced Iraqi man who fled from clashes, carries children in western Mosul, Iraq, June 3, 2017. REUTERS/Alaa Al-Marjani

BAGHDAD (Reuters) - About 100,000 children are trapped in extremely dangerous conditions in the remaining Islamic State-held enclave in the northern Iraqi city of Mosul, the United Nations said on Monday.

Children were being used as human shields by the insurgents or were caught in the crossfire of the battle, the United Nations Children Fund (UNICEF) said in a statement. Some had been forced to take part in the fighting. Hospitals and clinics had come under attack, it said. “We are receiving alarming reports of civilians including several children being killed in west Mosul,” UNICEF said. “Some were reportedly killed as they desperately tried to flee the fighting which is intensifying by the hour,”

A Reuters TV crew on Saturday saw the bodies of dozens of civilians, including children, lying in a frontline street, apparently killed while fleeing the enclave.

Iraqi government forces retook eastern Mosul in January and began a new push on May 27 to capture the remaining Islamic State-held enclave in the city’s western side.

The Mosul offensive started in October with air and ground support from a U.S.-led international coalition. It has taken much longer than expected as the militants are dug in the middle of civilians.

About 700,000 people, about a third of the pre-war population of Mosul, have already fled, seeking refuge either with friends and relatives or in camps.

“Attacks on civilians and civilian infrastructure including hospitals, clinics, schools, homes and water systems should stop immediately,” UNICEF said.