Ontario's Special Investigations Unit is investigating a police shooting in Mississauga on Tuesday night that has left a man in serious condition.

Peel police said the man crashed a vehicle into a garage after he was shot by police.

The shooting happened in the area of Southampton Drive and Eglinton Avenue West, near Winston Churchill Boulevard.

The incident began when undercover officers from the Peel police street crimes unit investigated a vehicle because of suspected drug activity at about 7:30 p.m., according to Const. Sarah Patten, spokesperson for Peel Regional Police.

In a news release Wednesday morning, the SIU said officers were there to make an arrest.

When police approached the vehicle, the driver drove at the officers.

"One of the officers fired several shots at the vehicle, striking the driver. And the vehicle then drove into a garage in the townhouse complex just behind me," Patten told reporters near the crash scene.

The SIU says the "person of interest" is a 28-year-old man.

Peel paramedics took the driver to a trauma centre. No one else was injured, Patten said.

An officer guards the scene of a police shooting before Ontario's Special Investigations Unit arrives. (Jeremy Cohn/CBC)

The SIU has been notified and was said to be on its way to the scene at about 10:30 p.m.

Police have closed roads in the area as officers investigate.

The SIU is called in whenever someone is injured in a confrontation with police, or there is an allegation of sexual assault against an officer.

Anyone with any information is urged to call Peel police and the SIU.