Toronto police say the suspects behind a brazen high-school robbery and shooting Thursday were on a "crime spree" and were responsible for a slew of similar crimes.

Police said during a news conference on Friday that in total 10 individuals have been arrested and charged with 21-robbery related charges in the west end of Toronto, Peel Region and York Region, including the shooting at Thistletown Collegiate Institute.

Thistletown Collegiate in Toronto's west end was locked down much of Thursday afternoon as police investigated an armed robbery. (Michael Cole/CBC)

"Anything that moved, these individuals wanted to rob," said Staff Insp. Mike Earl of Toronto Police.

Thistletown Collegiate Institute was locked down for three hours yesterday after four male suspects entered the school and robbed two students of their cellphones.

When they tried to rob a third student, he fled and was shot at in the school parking lot.

Police are confident that the shooter is now in custody, said Supt. Ron Taverner.

"We feel confident that we've ended a huge crime spree and we thank everyone for the co-operation, the calls, the information that we've received from the public," he told reporters.

Suspects allegedly attempted 2 more robberies Thursday

After the shooting and robbery at Thistletown Collegiate, the same individuals allegedly attempted two other robberies that afternoon, said Earl.

"Not only did they fire a shot at the victim at the school, once that had transpired, they went on to try and rob a wireless convenience store on Finch Avenue West, then further robbed a variety store on Weston Road," he said.

After witnesses spotted the licence plate of a car that had previously been reported stolen and seen at the earlier high school robbery, they reported it to police. Officers swarmed the area and located the car, near where the other robberies took place, said Earl.

When these individuals returned to this car, near Jane Street and Driftwood Avenue, police were waiting, said Earl.

Shortly afterward, police arrested at least five people at a nearby community centre.

More individuals were apprehended throughout Thursday afternoon into the early hours of Friday morning, said Earl.

The individuals arrested are expected to appear in court on Saturday.

Escalating violence

Eleven more search warrants are now being executed, Earl added.

"The investigation is continuing," he said.

Toronto police's hold-up squad have been investigating a string of robberies, which they say began on January 8, said Earl.

The suspects were allegedly robbing "mom-and-pop type convenience stores", gas stations and even people on the street, he said.

"They were armed with either a handgun or a shotgun or both during these robberies, and the violence escalated from going in and being quite passive in the initial robberies to pistol whipping people then finally firing a shot in the later stages," he told reporters.

Earl said there was "no doubt it would have got even worse", if these individuals had not been arrested.