At least seven people were injured following a shooting at a nightclub in the Canadian city of Toronto, police said, adding that one of the wounded was in critical condition.

Axar.az reports News Canada that Toronto police said emergency crews were called to District 45 on Finch Avenue West after 2 a.m. on Monday.

"We received several phone calls from patrons inside (the nightclub) for the sound of gunshots," Duty Inspector Stacy Davis told reporters on Monday morning.

Davis said that there were reports of an altercation inside the club, but there was no information on the suspect yet.

Police chief Mark Saunders said the shooting was "very solvable" based on the high number of witnesses present, encouraging attendees to come forward.

"I find it disturbing when you've got over 100 people and someone would be brazen enough to pull out a gun and start shooting," he said.

The owner of the nightclub, said he and around 250 people were at the establishment at the time of the shooting.

"I'm angry. I'm not happy about it. We planned for the night. We had over 40 security guards," he said.

The Toronto incident comes after two mass shootings in the US states of Ohio and Texas over the weekend claimed the lives of 31 people in total.