A Minneapolis Park Police officer was injured Tuesday afternoon after his firearm discharged during a struggle with a man suspected in a sexual assault at Mueller Park.

Police say the incident occurred around 1:15 p.m. when a 911 caller reported a man in the park was “inappropriately touching children.”

A responding Park Police officer found the suspect in a nearby alley, where the man ran and a foot chase followed. The suspect and officer then fought, and the officer’s gun fired once while still in its holster.

The officer was taken to Hennepin Healthcare with a lower arm injury described as minor. Authorities have not confirmed whether he was struck by the bullet. The suspect was not hurt.

Minneapolis Police Chief Brian O’Hara said the suspect is known to law enforcement and has prior convictions, including assault and criminal sexual conduct. The injured officer is a retired Minneapolis Police sergeant with three decades of service who has worked for the Park Police for the past five years.

The officer is on administrative leave while Minneapolis Police investigate the incident. Authorities have not released the suspect’s name, or whether he was taken into custody during the encounter.