A gunman opened fire in central Toronto on Sunday night, killing one and injuring 13 people including a child before being shot dead, police reported.

Toronto Police said they had responded to a call at around 10:00 pm (0200 GMT Monday) in the city's Greektown district.

“One female adult has died. One young girl in critical condition,” Toronto police said on Twitter, adding that all 14 victims were shot with a handgun.

Global News quoted a Toronto police source as saying the suspect is believed to have opened fire at police before killing himself.

Toronto police spokesman Mark Pugash said it was too early to say whether the shooting was terrorism.

Toronto Councillor Paula Fletcher told CP24 she heard that the gunman was emotionally disturbed.

“It's not gang related. It looks like someone who is very disturbed,” Fletcher said.

Councillor Mary Fragedakis also said she heard the gunman was disturbed.

The shooter was caught on camera prior to opening fire.

Witnesses described to local media hearing about 20 shots and the sound of a weapon being reloaded several times.

Jody Steinhauer, an eyewitness of the shooting, told CBC News that she was at a restaurant in the area when she heard what sounded like 10 to 15 blasts of firecrackers.

"We started to hear people scream out front," she said.

Ontario Premier Doug Ford tweeted out a message of solidary with the victims, saying: “My heart goes out to the victims and loved ones of the horrific act of gun violence in Toronto.

“Thank you to all the first responders for acting quickly to help everyone affected.”

The incident comes with Canada's largest metropolis concerned over a spate of shootings, more than 200, this year. About two dozen have been fatal.

Canada traditionally has relatively low levels of gun violence, particularly compared with its neighbor the United States.

Mayor John Tory said Sunday night's firearms violence is “evidence of a gun problem” in Toronto.

“Guns are too readily available to too many people,” Tory told a news conference two hours after the shooting took place.

He added that details of the latest incident remained sketchy.

“We have to figure out what happened here. We don't know,” he said.

Last week, Toronto police started implementing the enforcement component of their “gun violence reduction plan.” That includes around 200 additional officers on shift in particular neighborhoods between the hours of 7:00 pm and 3:00 am - when most shootings occur.

The Greektown shooting comes about three months after the city was shaken by the deaths of 10 people, most of them women, killed by a man with an apparent grudge against women who drove into them on a busy street in Toronto's north end.