Three senior ISIS military leaders and planners were killed in US-led coalition attacks in Iraq and Syria over the past two months, the coalition fighting the militants said in a statement released by the Pentagon on Friday.

Mustafa Gunes, an ISIS operative from Turkey, was killed in an air strike in Mayadin, Syria, on April 27, the statement said. Abu Asim al-Jazeri, an ISIS planner from Algeria, was killed in Mayadin on May 11, it said.

Abu Khattab al-Rawi, an ISIS military leader, was killed in al Qaim, Iraq, on May 18, the statement said. It said all three were foreign fighters but did not identify al-Rawi’s home country.

On the other hand, a US military investigation on Thursday acknowledged that civilians were killed in a US air strike on a building in the Iraqi city of Mosul in March during operations against ISIS militants.

The probe concluded that the US strike in the Al-Jadida district inadvertently triggered explosives placed in the building by ISIS fighters, causing it to collapse.

Air Force Brigadier General Matthew Isler, who oversaw the investigation, told reporters that 101 civilians inside the building were killed, four civilians were killed in the neighboring building, and 36 civilians were still not accounted for.

The coalition had been monitoring the area since the operation for western Mosul began weeks before. However, for two days before the strike took place, the coalition did not have overhead surveillance of the area because of the weather, Isler said.

When the 500-pound (227-kg) bomb was dropped on the building targeting the snipers, it triggered explosives inside the concrete structure, collapsing it onto civilians.

The United States and nearby Iraqi forces did not know there were civilians in the building or that it had been rigged with explosives, the probe found.