THUNDER BAY, Ont. - Thunder Bay police arrested a man who they say allegedly hit an on-duty officer in the face on Monday evening.

Police say the officer was investigating an alleged assault in Thunder Bay, Ont., when a man unrelated to the probe walked over and bumped into the fender of the officer's cruiser.

After the officer identified himself, police allege the man attacked him, hitting him in the face before running off.

Police say the officer chased the man on foot for several blocks and then arrested him.

They say the officer required stitches for a cut on his nose as a result of the alleged assault.

They say a 23-year-old local man has been charged with assaulting and resisting a peace officer.