BAGHDAD, Iraq – ISIS used chemical weapons against Iraqi forces taking part in the operation to recapture Mosul, injuring some security personnel, the Iraqi military said on Sunday.

ISIS has periodically carried out attacks using chemical weapons, but both the toll and the impact on military operations has been minimal and the militants’ bombs and bullets are far deadlier.

“The Daesh (ISIS) terrorist gangs tried to block the advance of our forces by using shells filled with toxic chemical material, but the effect was limited,” Iraq’s Joint Operations Command said in a statement, using an Arabic acronym for ISIS.

The attack on Saturday did not result in any deaths but did cause “limited injuries” among security personnel, the military command said.

The statement said that the forces attack were part of the massive operation aimed at recapturing the city of Mosul from ISIS, but did not specify if the attack took place in or outside the city.

Iraqi forces are fighting to recapture west Mosul from ISIS after retaking the eastern side earlier this year, while soldiers and pro-government paramilitaries are also operating west of the city as part of the operation.