Iraqi government forces paused in their push to recapture western Mosul from Islamic State militants on Saturday because of the high rate of civilian casualties, a security forces spokesman said.
The halt was called as the United Nations expressed its profound concern over reports of an incident during the battle on March 17 that killed or wounded dozens of people in the Islamic State-held al-Jadidah district of Mosul, apparently involving air strikes by Iraqi or U.S.-led coalition forces.
"We are stunned by this terrible loss of life," Lise Grande, the humanitarian coordinator for Iraq, said in a statement.
Civil defence officials and residents have said many people lay buried in collapsed buildings after air strikes against Islamic State insurgents triggered a big explosion.
The exact cause of the collapses was not clear but a local lawmaker and two residents said the air strikes may have detonated an IS truck filled with explosives, destroying buildings in the heavily-populated area.
Reports on the numbers of civilian casualties have varied but Civil Defence chief Brigadier Mohammed Al-Jawari told reporters on Thursday that rescue teams had recovered 40 bodies from collapsed buildings.
The coalition is investigating the reports.
Residents escaping besieged western Mosul have told of Iraqi and U.S.-led coalition air strikes demolishing buildings and killing civilians in several cases.
The insurgents have also used civilians as human shields and opened fire on them as they try to escape Islamic State-held neighbourhoods, fleeing residents said.
"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."
The U.S.-backed offensive to drive Islamic State out of Mosul, now in its sixth month, has recaptured the entire eastern side of Mosul and about half of the west.
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 Islamic State leader Abu Bakr al-Baghdadi declared a caliphate spanning large areas of Iraq and Syria in 2014.
"We need to make sure that taking out Daesh (Islamic State) 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 U.S. 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, U.S. 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 Islamic State 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.
The United Nations’ Grande said civilians were at extreme risk as the fighting in Mosul intensified and all sides must to do their utmost to avoid such casualties.
"International humanitarian law is clear. Parties to the conflict — all parties – are obliged to do everything possible to protect civilians. This means that combatants cannot use people as human shields and cannot imperil lives through indiscriminate use of fire-power," she said.