MISSISSAUGA, Ontario — Investigators on Friday were looking for two people who detonated a pail filled with projectiles inside a crowded Indian restaurant near Toronto late Thursday, wounding 15 people, three of them critically.

Chief Jennifer Evans of the Peel Regional Police called the bombing “horrendous,” but said there was no immediate indication that it was related to terrorism or a hate crime.

The blast took place around 10:30 p.m. at the Bombay Bhel restaurant in Mississauga, Ontario, a large city just west of Toronto. Sgt. Matt Bertram said the assailants had entered the restaurant and put down what appeared to be a pail or a paint can, which then exploded as the two fled down the street.

Rafael Concaceicao, a student from São Paulo, Brazil, told the Canadian Broadcasting Corporation that he was on the patio of a nearby restaurant when he heard the explosion at Bombay Bhel. He rushed to help, he said.