CHICAGO (STNG/WBBM) ― A Chicago police officer was bitten in the ankle by a pit bull early Monday on the South Side.

The incident occurred about 1:30 a.m. at 7935 S. Kenwood Ave., according to a South Chicago District police sergeant.

The officer and his partner were responding to a call at the Kenwood Avenue address and a pit bull appeared from an unknown location, "came at her and just bit' him,' according to the sergeant.

"They don't know where the dog came from,'' the sergeant said.

The bite broke the officer's skin, but did not cause serious injury. He was taken to a hospital for treatment.

The officers did not shoot the dog, which apparently let go of the officer on its own.  The pit bull is still on the loose as of 3 a.m.

No citations were issued, as police do not know who owns the dog, according to the sergeant.