A man has been arrested after allegedly slashing the side of a passenger's face with some kind of weapon in Ajax on Friday.

At approximately 10:45 p.m., the 18-year-old was travelling on a Durham Regional Transit bus when another male passenger started to harass him, police said in a statement Monday.

Police did not specifically say what the man did to harass the passenger, but he then pulled out an edged weapon and started to attack the victim.

The 18-year-old received serious but non-life-threatening injuries to the side of his face during the attack, which police say was unprovoked.

The victim was helped by other passengers who tended to his wounds until paramedics arrived on scene. He was then rushed to a nearby hospital to be treated.

The suspect fled the bus and was arrested a short distance away.

The suspect, who is also 18, has been charged with aggravated assault, assault with a weapon, carrying a concealed weapon and possession of a dangerous weapon.

Police said the suspect and victim did not know each other.

Anyone with more information about the incident is asked to contact Durham Regional Police at 1-888-579-1520, ext. 2528, or Crime Stoppers anonymously at 1-800-222-8477 (TIPS). Tipsters may be eligible for a cash reward of $2,000.