The Winnipeg Police Service says they are hoping to track down a witness to a violent stabbing that occurred on a transit bus.

Constable Jay Murray says that both the suspect and victim calmly entered the transit bus on Sunday. The two men did not know each other but engaged in an altercation while on the bus.

The suspect then allegedly stabbed the victim on the bus. The victim left the bus at approximately 3:00 p.m, immediately flagging down police officers in the area of Colony Street and Ellice Avenue, collapsing shortly after.

The 57-year-old victim was transported to the hospital in critical condition, where he later died from his injuries.

The Winnipeg Police Service says that the altercation was unprovoked.

Murray says that it is unusual to see random violence, but that they are currently seeing an increase, especially as the weather warms up.

"We have seen a number of violent incidents in Winnipeg (between people) that are not known to each other," Murray says.

Murray says officers quickly boarded the bus and were able to arrest the suspect. Police believe alcohol may have played a role in the attack.

The 46-year-old suspect is being charged with Manslaughter. 

During the short time between the stabbing and the arrest, a passenger left the bus before the police could question them. Police believe the passenger may not have known the altercation ended in death and was fleeing to avoid confrontation.

The Winnipeg Police Service says that they wish to speak with the passenger and is asked to call the Homicide Unit at 204-986-6508 or Crime Stoppers at 204-786-TIPS (8477).