Police say two male suspects fled the scene after detonating an "improvised explosive device."

Fifteen people have been injured after two men walked into an Indian restaurant and set off a bomb.

Canadian police said the male suspects fled the scene after detonating an "improvised explosive device" inside the Bombay Bhel restaurant in Mississauga, Ontario.

The attack happened on Thursday at about 10.30pm (3.30am Friday Irish time).

The wounded were taken to hospital after the explosion. Three were in a critical condition and taken to Toronto Trauma Centre for treatment.

The plaza where the restaurant is situated remained sealed off on Friday as emergency services continued to investigate the blast and establish a motive for the attack.

A witness, Andre Larrivee, told the Globe and Mail newspaper that he was watching television in his home when he heard the blast. "It was really loud," he said.

Peel Regional Police posted an image of the two male suspects on Twitter. One appeared to be carrying an object in his right hand. 

Both suspects fled the scene immediately after the attack.

The attack in Canada's sixth largest city, comes a month after 10 people were killed in Toronto when a man drove his rented van into a lunch-hour crowd on a busy street. Fifteen others were injured.