Commercial motor-cyclists have chased officers out of a police station in Akure, the Ondo State capital.
The protesters accused a policeman of killing a colleague of theirs at Arakale area of Akure.
A policeman reportedly attached to a filling station in the area was said to have fired shots into the air to scare the protesters away, but one of the shots hit and killed an okada rider.
The culprit reportedly fled to the A Division for refuge.
The motor-cyclists then mobilized themselves to the Divisional police station where they attacked policemen on duty.
Some officers scaled the fence and ran away while others struggled to take their vehicles out of the barracks.
Radio Nigeria Correspondent reports that bonfires were set in front of the A Division as the Okada riders demanded the release of the policeman who shot their colleague.
Ondo Police spokesman, DSP Fumilayo Odunlami, said she was yet to be briefed about the incident.
Reporting by Kayode Animasaun; Editing by Adeniyi Bakare