The officer with the anti-terrorism forces said Saturday that the attack occurred the night before in the al-Abar neighborhood, when ISIS fired a rocket loaded with chlorine. He said seven soldiers suffered breathing problems and were treated in a nearby field clinic.
The officer spoke on condition of anonymity as he was not authorized to release information, AP reported.
US-backed Iraqi forces are currently battling ISIS militants in the more densely-populated western half of Mosul. Iraqi officials say more than half of western Mosul has been retaken. The extremists were driven out of the eastern half of Mosul, Iraq's second-largest city, in January.