At least 33 former members of Iraqi security forces were killed in a U.S.-led coalition raid in western Mosul on Monday, according to a local police officer.

Federal police officer Abdullah al-Mayahi said IS militants had held dozens of former members of the security forces to question them about an alleged collaboration with the Iraqi army.

He said a coalition warplane mistakenly fired two missiles into a train station, where the captives were held.

“The strike killed 33 former security forces members and injured eight others,” he told.

According to al-Mayahi, a number of IS militants were killed and injured in the airstrikes.

“IS has tried to cover up his crime by claiming that the bombed site was hosting refugee families,” the police officer said.