The deaths have sparked renewed concerns about civilian casualties from coalition airstrikes targeting ISIS fighters in the city.

A senior Iraqi military officer said a

March 17 coalition airstrike on an explosives-laden ISIS truck

led to the deaths of dozens of civilians.

The coalition said a review confirmed one strike that day in the area where the casualties were reported. But US officials have not confirmed the senior Iraqi officer's account.

Both the Iraqi and US defense departments launched investigations Saturday into possible civilian deaths in airstrikes between March 17 and 23.

While those investigations continue, US Defense Secretary James Mattis said, "There is no military force in the world that is proven more sensitive to civilian casualties."

"We are keenly aware that every battlefield where an enemy hides behind women and children is also a humanitarian field, and we go out of our way to always do everything humanly possible to reduce the loss of life or injury among innocent people," Mattis said. "The same cannot be said for our adversaries."

US and Iraqi forces have been trying to regain control of Mosul — Iraq's second-largest city — from ISIS since October.

ISIS had a firm grip on Mosul since 2014, but suffered a major blow when Iraqi security forces

regained control of eastern Mosul in January

. But the arduous fight for western Mosul continues.

Life under ISIS rule

For Iraqis in recently freed parts of Mosul, the haunting memories of ISIS are still fresh.

One woman in the southern Wadi Hajer neighborhood said ISIS fighters forced her and her family from their home and took them to another house to be used as human shields. She said life under ISIS was humiliating and painful.

A grandmother in the same neighborhood said she lived with her son, his wife and their children as ISIS tormented the area.

She recalled a time when her family's water got cut off, and the whole family had to share one last remaining glass.

"I would go around and give my grandson a sip, and then the others," the grandmother said. "We would all take one sip at a time."