CHICAGO (CBS) — A Chicago Police sergeant is recovering after he fell on the job.

The sergeant was investigating a suspicious person in a gangway at 63rd Street and Rhodes Avenue, when he was hurt just after 11:30 p.m. Thursday.

Police say the officer struck his head on the ground.

He was not seriously hurt, Alfaro said, but his exact condition was unavailable early Friday.

The sergeant was not chasing anyone when he fell, and his injury has been deemed accidental, police said.

The Sun-Times Media Wire contributed to this report.