TORONTO -- Six teens were arrested and charged Monday in connection with an alleged sexual assault at an all-boys private school in Toronto as police said they were looking into more incidents and additional charges could follow.

Police said five teens, accompanied by their parents or lawyers, turned themselves in to police, while a sixth student was arrested on his way to school. They said the investigation continues into three other incidents -- one an alleged sexual assault.

Insp. Dominic Sinopoli said the six boys who attended St. Michael's College School each face charges of assault, gang sexual assault, and sexual assault with a weapon in connection with an incident that allegedly took place on campus and was captured on video.

"We have reason to believe there are more incidents and more videos," Sinopoli told a news conference.

The school, whose failure to promptly report the alleged assault and sexual assault to authorities has come under criticism, said it supported the decision by police.

"We believe charges are absolutely appropriate in these circumstances," the school said in a statement. "We will continue to work in full co-operation with the police as they continue their investigation and we are at their disposal."

St. Michael's, a Roman Catholic school that teaches grades 7 to 12 and is known for its athletics program, expelled eight students and suspended another one in connection with the alleged sexual assault in a locker room and another incident that police said involved hazing and was also captured on video.

Police sources have said the locker room incident involved a group of students on the football team pinning down another student and allegedly sexually assaulting him with a broom handle. Those sources said the hazing incident involved members of the basketball team bullying a student in the washroom and soaking him with water.

Sinopoli said Monday that the victim of the alleged sexual assault was doing OK.

"He has gotten the support he needs and deserves," he said.

Sinopoli said detectives were informed about the alleged sexual assault through the media on Wednesday. As a result, he said, an officer was dispatched to the school.

"Prior to arriving, Toronto police corporate communications received further information from the media indicating the expulsions were believed to be related to sexual assault involving an object," he said. "When the officer arrived and after speaking with the principal, he confirmed expulsions...were in response to a video that showed or depicted a sexual assault."

The school initially said it had informed police of two incidents, including the alleged sexual assault of a student, on Monday. However, the school's principal, Greg Reeves, admitted in a series of media interviews on Sunday that he did not report the alleged sexual assault on Monday because the alleged victim had not yet told his family about the incident.

Sinopoli said the school should have reported the incident immediately.

A number of legal experts said that in Ontario, schools have an obligation under the Child and Family Services Act to report instances where a child aged 15 and under has been or could be sexually assaulted to the Children's Aid Society.

The school has said the Children's Aid Society was not contacted, and though the ages of the students involved in the alleged incidents are not known, sexual abuse lawyer Rob Talach said he would have expected the school to call child protective services.

"I would think as an educator you would err on the side of caution and say, 'I'm not sure if everybody in there was over the age of 16, so I'm going to report it to CAS,' and then CAS can bring in the police," he said.

Sinopoli said the investigation has expanded and police are now looking into another case of sexual assault and two more alleged assaults involving at least four victims.

"More than 50 witnesses have been identified and more information comes to us daily," Sinopoli said. "We also know there are several videos being circulated. We are in possession of these videos."

He also called on students and any one in possession of the video of the alleged sexual assault to delete it immediately from their cellphones or other devices as the clip constituted child pornography.

"We are very concerned about the distribution of the videos on social media," Sinopoli said. "The unintended consequences are far reaching and detrimental to the recovery of the victim."

In a statement released Sunday, St. Michael's said it's launching an "independent examination" into what it called "underlying attitudes and behaviours inconsistent with its culture and values."

Reeves said an "external review committee" will be created in the next two to three weeks. He hopes a preliminary examination will be done by spring, with a more in-depth investigation to be completed by next summer.

Sinopoli acknowledged that tensions in the school were high due to the recent events. St. Michael's principal was unable to attend the news conference Monday due to a security threat at the school.

Police said they had also received unconfirmed reports of threats against St. Michael's students on social media and in public.

"We want to reiterate that we are monitoring social media and we'll act on any reports of reprisals, retaliation, violence or threats of violence," Sinopoli said.