Three people were critically injured in a crash in Ottawa's Vanier neighbourhood on Tuesday, not long after a short Ottawa police pursuit in the ByWard Market.

At about 1:15 a.m., an Ottawa police officer in a marked cruiser tried to stop the driver of a Pontiac G6 car in the ByWard Market, near George and Cumberland streets.

The driver fled and the officer pursued for a few moments, then called off the pursuit, according to Ontario's Special Investigations Unit.

Not long after, the driver of the Pontiac crashed into a Honda Accord at the intersection of the Vanier Parkway and McArthur Avenue.

3 people critically injured when car flees police in ByWard Market, gets into head-on crash. <a href="https://t.co/jjFd9gotrb">https://t.co/jjFd9gotrb</a> <a href="https://t.co/8G6UXB5zB3">pic.twitter.com/8G6UXB5zB3</a> —@amkfoote

Man, woman, ejected from car

The Honda rolled over and the two young people inside were ejected by the force of the crash, according to Ottawa paramedics:

A 24-year-old man suffered critical closed head injuries, neck injuries and multi-system trauma. He was unconscious and needed help breathing from paramedics when they arrived.

A 21-year-old woman suffered critical, life-threatening head injuries and multi-system trauma. She has since stablized and is now listed in serious condition.

The 37-year-old man driving the Pontiac suffered serious closed head injuries and a serious leg fracture. He was unconscious as he was being extricated from his vehicle by firefighters and was taken to hospital in critical condition.

All three were taken to the Ottawa Hospital's Civic campus trauma unit.

The SIU investigates cases involving police that cause serious injury or death, as well as allegations of sexual assault. Four SIU investigators and two forensic investigators have been assigned to the case.

Anyone who may have witnessed the incident is asked to call the SIU's lead investigator at 1-800-787-8529.

Sections of Vanier Parkway and McArthur Avenue were closed after the collision but have since reopened.