Outside locked down Bendale Business and Technical Institute near Midland Avenue and Lawrence Avenue on Tuesday afternoon. (CBC)

A 16-year-old student is in critical condition in hospital after he was shot outside a Toronto high school, one of three shootings in the city on Tuesday that left two men dead.

The school shooting happened just before noon outside Bendale Business and Technical Institute near Midland Avenue and Lawrence Avenue.

According to Toronto police Chief Bill Blair, the 16-year-old became involved in an altercation "with a number of young men" when one pulled out a gun and fired.

By the time police arrived, the injured teen had managed to get inside and was found in a pool of blood in the main hallway.

Blair said the teen was shot once in the stomach or chest, and was rushed to Sunnybrook Hospital, where he is in critical condition.

The victim is a student at Bendale, but Blair refused to give any further information.

One man was killed and another sent to hospital after a shooting in northwest Toronto at a playground near Jane Street and Driftwood Avenue.

Police arrived on the scene around 5:15 p.m. to find two victims had been shot on a basketball court. One was pronounced dead at the scene. The second victim was rushed to hospital and is expected to live, according to police.

Three suspects were seen speeding away in a silver or grey sedan southbound on Jane Street.

And in Mississauga, a man believed to be in his 20s was reportedly shot dead around 4 p.m. while he was sitting inside his car on Reindeer Drive, near Derry and Airport roads. Witnesses said the man was shot at point-blank range as he was waiting for someone to enter the car.

Police were still on the scene Tuesday evening collecting evidence.

Looking for suspect in school shooting

In the Bendale shooting, a person of interest was taken into custody for questioning around 4:30 p.m., but has not been named as a suspect.

Police said earlier in the day they were looking for one suspect described as "a male, black, 18 to 19 years old, approximately 5-foot-8, and ... last seen going [through] Donwood Park onto Norbury Crescent," according to Const. Wendy Drummond.

At least three other males were involved in the fight and ran away after the shooting. They are being sought by police.

A nearby resident has reported finding a black hooded sweatshirt on her property about two blocks south of the school. Police roped off the yard and believe the clothing may have been worn by the shooter or his accomplices.

Gerry Connelly, the Toronto District School Board's director of education, was at the school Monday afternoon.

Connelly called the shooting "tragic."

"We cannot prevent every single incident," she told reporters on the front lawn of the school, but she said the board is taking "every step it can to ensure the safety of the students."

Bendale and at least three neighbouring schools — David and Mary Thomson Collegiate, Donwood Park Junior and Highbrook Learning Centre — were locked down for most of the afternoon while police hunted for the suspects.

The lockdowns were lifted shortly after 2 p.m.

A couple of dozen concerned parents and area residents gathered behind yellow police tape as news helicopters buzzed overhead, with all eyes fixed on the school's doors waiting for any sign of movement.

Vera Kusakovski, whose son attends Bendale, waited outside the school after getting a phone call from him saying he was safe but locked down. She vowed not to leave until she was certain her son was safe.

"I just want to see him, that's all," she sobbed. "When I see him, I'll be OK."

Another parent rushed to the scene from her nearby workplace when she got a text message about the shooting. The woman said she attended Bendale, an alternative school of about 600 students interested in business and technical careers, and never thought it was dangerous.

"We never had this when we went here," said Cindy Taylor, whose 14-year-old daughter is a Bendale student. "We did our fighting with our hands or our mouths, but nothing with weapons."

Police say they have no information yet on the possible motive, but are interviewing students and staff who may have information.

Police patrolling some schools

This week, following last week's start of the new school year, armed police officers began patrolling 27 Toronto high schools, but Bendale is not among them.

Coincidentally, it was almost exactly a year ago — on Sept. 11, 2007 — that 16-year-old Dinesh Murugiah was stabbed to death in a laneway behind nearby Winston Churchill Collegiate Institute at Lawrence Avenue East and Kennedy Road.

Winston Churchill is now one of the schools with an armed police officer on site during the school year.

In May 2007, Jordan Manners, 15, was shot and killed inside C.W. Jefferys Collegiate Institute in northwest Toronto. That slaying prompted increased security measures at Toronto schools.

With files from the Canadian Press