At least 15 people have been injured in what the police called an improvised explosive attack on Thursday night near Toronto.

The police are hunting two hooded men they say planted a bomb in the Bombay Bhel restaurant in Mississauga, Ontario.

A witness described people screaming and bleeding. He said there was a children's birthday party in the restaurant at the time.

There has been no indication of terrorism or a hate-motivated attack so far.

Fifteen people were injured when a bomb went off at a restaurant in Canada late on Thursday night, according to authorities.

The police say two hooded men planted a bomb in Bombay Bhel, an Indian restaurant in Mississauga, not far from Toronto.

They issued an image showing two figures walking out of the restaurant shortly before the blast hit, about 10:30 p.m. local time.

The entrance to the Bombay Bhel restaurant after the blast. Reuters

A map showing the distance from downtown Toronto to the site of the attack. Google Maps/Business Insider

Three people were treated in critical condition after the attack but are now in stable condition. Twelve others were taken to the hospital but have since been released.

The victims' ages ranged from 23 to 69 years old, the police said on Friday.

Authorities issued descriptions of the two men and appealed to the public to help identify them. Both had covered their faces.

—Peel Regional Police (@PeelPoliceMedia) May 25, 2018

—Peel Regional Police (@PeelPoliceMedia) May 25, 2018

So far it isn't clear why the attack took place. Peel Police Chief Jennifer Evans told reporters on Friday morning that there was no indication it was a terrorist attack or a hate crime but that officials were not ruling anything out.

A witness who lives near the site of the explosion told the broadcaster CBC that he heard people screaming and that the victims of the blast were "bleeding so much."

Andre Larrivee said:

"Glass was broken in the street. There was a child's birthday party. Everything was destroyed. Lots of blood in the floor. Many people were screaming.

"They were trying to run out from the restaurant. There was a guy with glass inside his eyes. Many people were bleeding so much."

Jeremy Cohn, a video journalist for Global News Toronto, published this clip of emergency vehicles flooding the street near the restaurant.

Tony Smyth, a video producer with CBC, posted pictures of people leaving the area after the attack.

The attack took place roughly 19 miles from downtown Toronto, which was hit by an attack only one month ago.

The police arrested a 25-year-old accused of steering a van down a sidewalk in the city, killing 10 people and injuring more than a dozen others.