Displaced Iraqis flee their homes as Iraqi forces battle with ISIS militants, in western Mosul, Iraq March 24, 2017.

Iraqi government forces paused in their push to recapture western Mosul from ISIS militants on Saturday because of the high rate of civilian casualties, a security forces spokesman said.

Residents escaping the besieged area have told of Iraqi and US-led coalition air strikes demolishing buildings and killing numerous civilians.

The insurgents have also used civilians as human shields and opened fire on them as they try to escape ISIS-held neighborhoods, fleeing residents said.

The US-backed offensive to drive ISIS out of Mosul, now in its sixth month, has recaptured most of the city. The entire eastern side and about half of the west is under Iraqi control.

But advances have stuttered in the last two weeks as fighting enters the narrow alleys of the Old City, home to the al-Nuri mosque where ISIS leader Abu Bakr al-Baghdadi declared a caliphate spanning large areas of Iraq and Syria in 2014.

“The recent high death toll among civilians inside the Old City forced us to halt operations to review our plans,” a Federal Police spokesman said on Saturday. “It’s a time for weighing new offensive plans and tactics. No combat operations are to go on.”

Local officials and residents said on Thursday that dozens of people were buried in collapsed buildings after an air raid against ISIS triggered a huge explosion last week. Bodies are still being pulled from the ruins.

The coalition has said the reports are being investigated.

“We need to make sure that taking out Daesh (ISIS) from the Old City will not cost unwanted high casualties among civilians. We need surgical accurate operations to target terrorists without causing collateral damage among residents,” the Federal Police spokesman said.

An army statement published in the al-Sabah state newspaper said that future operations would be carried out by ground troops highly trained for urban combat.

“Our heroic forces are committed to the rules of engagement which ensure protection of civilians,” the statement said.

A US deputy-commanding general for the coalition told Reuters on Friday that the solution could lie in a change of tactics. The Iraqi military is assessing opening up another front and isolating the Old City, where the militants have put up fierce resistance, US Army Brigadier General John Richardson said.

Fleeing residents have described grim living conditions inside the city, saying there was no running water or electricity and no food coming in. Aid agencies say as many as 600,000 civilians remain in the western half of Mosul.

But families are streaming out of the northern city, Iraq’s second largest, in their thousands each day, headed for cold, crowded camps or to stay with relatives. Hunger and fighting are making life unbearable inside.

The Iraqi Observatory for Human Rights said that since the campaign on western Mosul began on Feb. 19, unconfirmed reports said nearly 700 civilians had been killed by government and coalition air strikes or ISIS actions.

The militants have used car bombs, snipers and mortar fire to counter the offensive. They have also stationed themselves in homes belonging to Mosul residents to fire at Iraqi troops, often drawing air or artillery strikes that have killed civilians.