Durham regional police say the incident happened at about 10:45 p.m. Friday when a male passenger began harassing another male passenger on a Durham Regional Transit bus to Ajax, east of Toronto.
It's alleged the first passenger pulled out an edged weapon and attacked the victim, leaving him with serious but
non-life-threatening wounds to the side of his face.
The victim was assisted by other passengers until paramedics arrived and then was taken to hospital where he was treated for his injuries and released.
Police say the suspect fled the bus, but was found with the assistance of a canine unit and arrested without incident by police a short distance away.
Both of the passengers were 18 years old, but police say they did not know each other.