The military said it determined that warplanes struck ISIS fighters and equipment March 17 in an area of west Mosul where there are allegations of civilian casualties. The coalition is now investigating whether those casualties occurred, how they occurred and how many civilians may have been killed, according to a US defense official.
At the same time, the US military is trying to determine whether there were additional airstrikes between March 16 and March 23 that also may have resulted in civilian casualties in western Mosul neighborhoods, the official said.
"Clearly it seems civilians were killed and injured," the official said.
It is still unclear exactly what took place, the official said. The official said one theory is that a number of airstrikes occurred and the death toll cited in social media and with activist groups is a cumulative total over several days. Claims on social media have said more than 200 were killed.
The US-led coalition is strongly looking at the possibility that ISIS put civilians in these areas as human shields, the official said.
Also Saturday, Iraq's Ministry of Defense opened an investigation into an "aerial bombardment incident" that took place in the same area of the city on March 22 and 23, said Col. Laith Al-Nuaimi, a ministry spokesman.
Bashar al Kiki, chairman of the Nineveh Provincial Council, told CNN Saturday that as many as 200 people were killed those days in "indiscriminate airstrikes" he blamed on Iraqi and coalition air forces in the western Mosul neighborhoods of al Jadidah, al Amel and al Yarmouk.
The US Central Command report doesn't mention strikes on March 22 or 23.
US and Iraqi forces are making an all-out push to regain Mosul from ISIS. Iraq's second-largest city has been under the terrorist group's control since 2014.
The US Central Command said in a statement Saturday that it has opened a formal probe "to determine the facts surrounding this strike and the validity of the allegation of civilian casualties."
"The coalition respects human life, which is why we are assisting our Iraqi partner forces in their effort to liberate their lands from ISIS brutality," the statement said.
"Our goal has always been for zero civilian casualties, but the coalition will not abandon our commitment to our Iraqi partners because of ISIS's inhuman tactics terrorizing civilians, using human shields, and fighting from protected sites such as schools, hospitals, religious sites and civilian neighborhoods."
The US military is also investigating allegations
of civilian casualties during two recent airstrikes in Syria.
New tactics in western Mosul
The head of the Mosul city council, Basma Baseem, told CNN Friday that the recovery operation was continuing in the west Mosul neighborhoods and that the death toll would likely rise.
Anger is high over airstrikes in those neighborhoods.
Kiki demanded an end to military operations in the area until the safety of civilians can be guaranteed. "Most of (those) killed are civilians, among them children and women," he said.
Local and UN officials have said hundreds of thousands of civilians are trapped in areas under ISIS control in western Mosul.
The United Nations also said it is "profoundly concerned" over reports "of a high number of civilian casualties" in the city's al Jadidah section this week.
Determined to keep civilians out of harm's way, Iraqi security forces adopted new tactics Saturday in their quest to recapture western Mosul from ISIS.
Mortars are being used on a smaller scale and are only targeting specific areas, said Col. Abdul Rahman Al-Khazali, an Iraqi Federal Police media adviser.
Police and the rapid response units pushed forward with more snipers and drones and more soldiers on foot, he said.
"We have reached the old city. It's more complicated warfare," according to Lt. Col. Abdul Amir Muhammadawi, spokesman for the rapid response teams.
"The old city has old buildings and small alleyways, and to protect the civilians, we need new tactics."