Toronto police Chief Mark Saunders said a nightclub shooting that left five people injured early Monday is "very bothersome," but given the number of witnesses, the crime is "very solvable."

During a news conference following a violent Simcoe Day weekend in the city, Saunders said that from Saturday to Monday, police were called to 11 separate firearm incidents.

Shortly before 5 p.m. ET on Monday, police responded to another gun-related incident in the Lawrence Heights area just south of Yorkdale shopping mall. One man was taken to hospital with gunshot injuries, which Toronto police and paramedics say were serious but non-life-threatening. A second victim made it to hospital on their own, police said.

Several hours later, police said multiple gunshots were heard in an area in the city's northwest. Police located one victim suffering from gunshot wounds. The victim's injuries are not believed to be life-threatening, police say.

A total of 17 people were left with gunshot wounds over the long weekend.

Thirty-three per cent of those incidents happened in the northwest end of the city, Saunders said.

Along with the nightclub shooting in suburban North York, the incidents included:

A Sunday morning shooting at an Airbnb-rented mansion on the Bridle Path, an upscale residential area in North York, that left one person injured.

Gunshots in Liberty Village, a condo-dominated area of downtown, that left one male victim with non-life-threatening injuries.

Two victims injured at the busy downtown intersection of Church and Adelaide streets.

Two victims shot in the area of Dufferin Street and Lawrence Avenue West, in the city's northwest end.

Police said they found five victims at the nightclub, including one male in life-threatening condition and four others, including two females, in non-life-threatening condition. A spokesperson for Toronto police said Monday afternoon that two more victims from the nightclub later showed up in hospital, revising the total number of victims from five to seven.

But police later said they have not been able to confirm that the two additional people who turned up at hospital with gunshot wounds were shot at the nightclub, revising the total number of victims back to five.

Police have yet to release details about the victims, including ages and identities.

"I find this one very bothersome," Saunders said.

Insp. Stacey Davis of the Toronto Police Service said multiple calls came in just after 2 a.m. ET from the District 45 lounge on Finch Avenue West near Keele Street.

Davis said there was an altercation near the back of the club's interior when shots were first fired.

The club was packed at the time of the shooting, Officer Stacey Davis of the Toronto Police Service said. (Jeremy Cohn)

Two victims left the club before police arrived and took themselves to hospital.

Davis said that after the shooting, patrons leaving the nightclub were in emotional distress.

"It's very concerning … the club was packed with patrons."

Saunders said investigators found shell casings inside and outside the club. They are reviewing security camera footage from inside the club to get a better sense of what happened and to identify a suspect or suspects. He also asked witnesses to call 31 Division or Crime Stoppers.

"We think this one is very solvable," he said. "There were a lot of people that were there."

Saunders told reporters he is putting "additional resources" into areas where he feels a police presence may help deter further gunplay. He did not elaborate on what that would look like.

Mayor renews call for handgun ban

On Monday, Mayor John Tory released a statement calling the recent rash of gun violence "absolutely unacceptable."

"I know Toronto police are working non-stop to find those responsible for these shootings and to bring them to justice," Tory said. "I urge anyone with information that could help investigators solve these shootings to call police or Crime Stoppers."

Tory also repeated his calls for a handgun ban. City council debated a handgun ban in June, despite the fact different levels of government have to be involved.