The Pentagon’s release of the footage on Thursday is part of a probe that the US has pledged to conduct into the offensive.

Pro-government tribal leaders in western Iraq say 19 of Lahaibi clan fighters were killed and several wounded in the US airstrikes on Wednesday.

The fighters had been engaged in fierce clashes with Daesh terrorists close to Qayara, south of Mosul.

The Pentagon said the airstrikes were carried out at the request of the Iraqi army.

Operation Inherent Resolve (OIR), the US-led coalition fighting the Daesh (ISIL) terrorist group in Iraq and Syria, said it had conducted an airstrike on a building near Kharaeb, a village south of Mosul that was being used by ISIS.

"We are aware of the reports that Sunni tribal fighters were in the building that was struck, and we are taking those reports seriously," OIR said in a statement announcing a joint investigation with Iraqi security forces.

Last December, over 20 Iraqi soldiers were killed and 30 were injured in an airstrike carried out by the US military.

Last month, 62 Syrian forces were also killed in airstrikes by US-led coalition jets on army positions near Deir Ezzor military airport.

The United States and some its allies have been carrying out airstrikes in Iraq and Syria since 2014 allegedly targeting ISIS terrorists.

Iraqi forces and their allied Shia and Sunni forces are closing in on the northern city of Mosul which fell to ISIL terrorists in 2014.

The US-led coalition has done little to stop Daesh's advances in parts of Syria and in Iraq.

Some analysts have criticized the US-led military campaign, saying the strikes are only meant to benefit US weapons manufacturers and destroy the two countries' infrastructure, Press TV reported.

219