The province's Special Investigations Unit is probing a police shooting in Toronto's east end that sent a suspect and bystander to hospital.

The SIU says York Regional Police were conducting an undercover drug investigation and followed a suspect to the Kingston Road and Morningside Avenue in Scarborough over the noon hour.

When police moved in to make an arrest, one officer fired a shot at the 22-year-old male suspect while he was seated inside his vehicle.

The suspect was hit in the chest but the wound was described as superficial. He drove away to a nearby home, believed to be his girlfriend's house, before he entered the Rouge Valley Centenary Hospital under his own will, the SIU said.

During the earlier arrest attempt, a man on his bicycle was knocked to the ground during the melee. The cyclist, who is in his late teens or early 20s, suffered cuts and bruises.

SIU spokesman John Yoannou described the cyclist as a "bystander."

The York and Toronto police forces are not commenting on the incident because the SIU is involved.

The SIU is a civilian agency that investigates cases of serious injuries and deaths involving police.

With a report from CTV Toronto's John Musselman