Durham Regional Police say a driver killed in a head-on collision between a car and a school bus on Friday evening was a 28-year-old Oshawa man.

Investigators are now appealing to another driver who was reportedly nearby at the time of the crash to come forward.

The deceased man's name was not released. Police said he was pronounced dead at the scene after he veered a black Infinity sedan into the incoming northbound lane, hitting a bus with 14 students, a rugby team coach and a driver.

No one on the bus was seriously injured.

According to a police news release, witnesses said the black sedan was "driving aggressively" northbound on Simcoe Street in Oshawa shortly before slamming into the school bus. 

Investigators are now looking for the driver of a white cargo van that was also driving southbound, in front of the Infinity sedan, for a time before the collision. 

Police said since roads conditions and weather were favourable at the time, they must consider the possibility that drugs or alcohol were a factor in the crash. 

Anyone else who may have information are encouraged to contact police. Tipsters may be eligible for a $2,000 reward.