MONTREAL -- A 42-year-old bystander has been seriously injured following a collision involving a Montreal police car.

Quebec's police watchdog says the woman was hit by a cruiser that was pursuing a suspect in Montreal's Mercier--Hochelaga--Maisonneuve borough just before 11 a.m. this morning.

The watchdog says the four-kilometre police chase began after the suspect refused to stop when pulled over.

The fleeing driver hit several other cars, including police cars, before finally coming to a stop after hitting a lamppost.

The driver was not injured and is currently in custody.

The watchdog will probe the incident with the help of Quebec City police.