A "swarming" attack in downtown Toronto that left a man dead on Sunday may have started when eight teenage girls tried to take a liquor bottle from him.

Toronto police provided new details Tuesday on the incident that occurred in the area of York Street and University Avenue, steps from Union Station, just after midnight on Dec. 18.

Speaking to reporters, Det.-Sgt. Terry Browne with the Toronto police homicide unit said a 59-year-old man had a liquor bottle and was with a companion when a group of teenage girls allegedly attempted to steal it.

"We can't say with certainty, but our belief is that (the girls) were trying to remove a liquor bottle that he was in possession of," Browne said.

The girls then allegedly assaulted and stabbed the man, leaving him with life-threatening injuries.

Browne said paramedics were flagged down by a group of individuals in the area who notified them about the assault.

"Emergency medical services staff commenced medical intervention. They realized that the victim had suffered what would (be) described as stab wounds," he said.

The victim was rushed to the hospital, where he was pronounced dead.

Browne said the girls -- three 13-year-olds, three 14-year-olds and two 16-year-olds -- were later arrested nearby.

"And as a result of quick work by officers in 52 Division, these females were able to be located and apprehended," Browne said.

They have been charged with second-degree murder. They appeared in court on Sunday and were remanded into custody. The girls cannot be identified under the terms of the Youth Criminal Justice Act (YCJA).

"I can't recall ever seeing a swarming type event with such young female suspects that has led to the death of somebody. This is the first that I can recall," Browne said, adding that his unit is seeing a "concerning trend" of younger people being involved in crime.

While he did not call the group a gang, Browne said what the girls allegedly did could be described as "swarming."

Browne said the parents of the eight girls had been notified as police are obliged to do so under the YCJA.

"We were able to contact the parents of each one of these eight individuals. And all families were engaged in the process," he said.

Browne noted it is unclear how long the girls have known each other as they come from different parts of the city.

"They met each other through social media," he said. "We don't know how or why they met that evening and why the destination was downtown Toronto."

When asked if any of the girls were known to police, Browne said three had prior contact with police services.

During the arrest, a weapon was also seized, which Browne described as sharp-edged. He did not specifically identify what it was.

Meanwhile, police have not released the name of the victim as they are yet to notify his next-of-kin. Browne said the victim recently moved to the shelter system but has a very supportive family in the area.

Brown said police do not have evidence to suggest that the victim and his companion knew the eight girls.

"It appears to be just a random, isolated (incident). There was a potential target available and for whatever reason, they all decided to act in concert to remove an item from him, which led to this tragic event," Browne said.

Police have established a dedicated website where people can submit evidence, including videos, about the incident that could help in the investigation.

Browne said investigators are particularly looking to speak to anyone who was in the area at the time and had interaction with the group of girls.

"We have information to believe that this same group of eight young women were involved in an altercation earlier," he said.

"If you have something, please share that with us because we would like to get any and all information available."

Mayor John Tory released a statement regarding the incident, calling it "unacceptable."

"While we are continuing to learn details of this murder, I am deeply disturbed by the allegations made public so far. Everyone in our city deserves to be treated with dignity and respect," Tory said.

"I am so saddened to know that a man has lost his life in this way. Toronto Police have made several arrests in this case – I am extremely troubled by the young age of those accused and by the number of people allegedly involved in this murder."

Anyone with information can also contact homicide investigators at 416-808-7400, Crime Stoppers anonymously at 416-222-TIPS (8477) or www.222tips.com.