(CNN) -- A woman was killed and 13 others injured in a shooting in Toronto on Sunday night, Police Chief Mark Saunders said.
The suspect is also dead, Saunders said.
The shooting victims are being treated for their injuries and their conditions were not immediately known. But one of the victims -- a young girl -- is in critical condition, Saunders told reporters late Sunday.
Shots rang out shortly after 10 p.m. ET in the Toronto's Greektown neighborhood.
'Every possible motive' being investigated
It's not clear what motivated the shooter, police said. They're investigating "every possible motive, including terrorism," Saunders said.
Toronto Mayor John Tory urged people not to draw any conclusions and let police investigate the shooting.
The shooter, who had a handgun, died from an apparent gunshot wound, but it's not clear if it was self-inflicted or as a result of exchanging gunfire with police, Saunders told reporters.
A witness who was standing near the scene told CNN partner CTV that he heard about 20 shots and the sound of the weapon being reloaded repeatedly.
"And then, I saw the carnage as I ran down the street here to kind of follow the gunfire," the man told the station, who described the scene as "pretty crazy."
"I saw at least four people shot," he said.
The victims were sent to trauma centers throughout the city, Toronto Police Sgt. Glenn Russell told CNN.
Local resident Andrew Van Eek told CNN partner CBC that he looked out his window after hearing gunshots.
"There was a lot of commotion in the street," he said. "I saw somebody come just down the sidewalk and shoot into Demetres restaurant."
Van Eek described the suspect as a white male aged in his early to late thirties and wearing black clothing.
Another witness, Jody Steinhauer had been dining with her family at Christina's, a Greek restaurant, when she heard what she thought was the sound of firecrackers. Then she was told to run to the back of the restaurant.
"We started to hear people scream out front," Steinhauer told CBC.
Witnesses were transported by buses to multiple offices to speak with investigators, Russell told CNN.
The crime scene covered a bit of distance, Saunders said, and police asked people to please contact them with any information they may have. Detectives began processing several scenes connected to the shootings.
City grapples with gun violence
Doug Ford, the premier of Ontario, tweeted Sunday night: "My heart goes out to the victims and loved ones of the horrific act of gun violence in Toronto."
Mayor Tory said guns were too accessible in his city
"We have a gun problem in that guns are readily available to too many people," he said.
"The police are doing their best but they're operating under extraordinarily difficult circumstances to deal with these guns and we'll see what they conclude from this case but it's evidence of a gun problem, clearly."
On Friday, the city rolled out a program to put 200 more officers on the streets of at-risk neighborhoods between 7 p.m. and 3 a.m. to combat gang violence, according to CTV. It's not clear if Greektown was included in that program.
Reporting the announcement of the program earlier this month, CTV reported that by July 8 there had been more than 200 shootings in Toronto and 26 fatalities. It said that by the same time the previous year there had been 188 shootings -- resulting in 17 deaths.
It said the extra staffing was intended to last for eight weeks, after which police would "reevaluate their needs."
In total, CAN $15 million ($11.4 million) had been set aside for efforts at curbing gun violence in Toronto, with some money going to community programs aimed at stopping youth joining gangs, CTV quoted Tory as saying.
Neighborhood known for its Greek population
However, an unnamed witness on Sunday expressed shock that Greektown had been the location of a shooting.
"It's the street where families come. They were all out tonight walking, having their dinner ... it's just unbelievable in this neighborhood," they said.
The Greektown Business Improvement Association says the area -- also known informally as "The Danforth" for its Danforth Avenue location -- is North America's largest Greek neighborhood.
Its website tells visitors to visit and "experience a neighborhood alive with interesting restaurants, boutiques, shops, markets, cafes, and a host of wonderful experiences."
According to the 2016 Census, Greek was the second most commonly spoken language at home -- behind English -- in the Toronto-Danworth city ward that contains Greektown. Six percent of the ward's immigrant population was Greek-born.