Durham police say they are looking for a suspect after one man allegedly struck another in the head with a brick at an Oshawa park, leaving him in life-threatening condition. 

It happened at around 6:40 p.m. on Aug. 28 at Memorial Park, at Simcoe Street South and John Street.

The suspect fled the area after striking the other man with the brick, police said.

Officers arrived and administered CPR to the victim before he was transported to a Toronto-area trauma centre in life-threatening condition.

Police told CP24.com Monday that the victim is expected to survive, but remains in serious condition.

Officers searched the area after the assault, but were not able to locate the suspect.

He is described as a white male between 20 and 30 years of age, standing around six feet tall with a medium build.

It's still not clear what motivated the assault.

"The relationship between the suspect and victim, and the circumstances leading up to the assault, are still being investigated at this time," police said in an email.

Police are asking anyone with information or video from the area to reach out to investigators or call Crime Stoppers and anonymously.