Multiple parties over the last three weeks — that high schoolers are learning of through social media, including a "Gossip Girl"-esque website — have resulted in "swarming-style" robberies, stabbings and assaults, according to Toronto police.

Most recently, police received reports of three separate incidents in connection with a party in the area of Rosedale Park on Sept. 16.

Police said victims aged 14 to 16 were allegedly robbed and assaulted and targeted by older teenagers.

According to police, there were approximately eight to 10 boys and girls — wearing hooded sweatshirts and masking their faces with bandanas — involved.

Residents said it quickly escalated to a chaotic situation.

"The numbers surprised us," said Lewis Reford, from the North Rosedale Association. "It seemed like between 9 p.m. and 11 p.m., the kids just didn't stop coming."

Residents told CBC Toronto they saw teenagers passed out on the street from what they believe to be excessive drug and alcohol use and were concerned for the safety of the youth.

Residents also said that when police arrived, the kids scattered all over the neighbourhood and ended up in backyards.

"In this instance, it didn't end well," Redford said.

Gossip website leading teens to parties: parents

Hundreds of teens have discovered the park parties through social media and various websites, according to police.

Parents have also expressed concern over a "Gossip Girl"-esque website, which is reportedly sharing rumours about teens from Toronto-area high schools.

The Toronto District School board told CBC Toronto that it is aware of the website, but does not have control over the content that is posted.

"It's important to note that content posted online that has a negative impact on the climate of a school can result in possible disciplinary action in cases where the poster's identity is known. In this specific case, the identity of the poster is not known by staff," said TDSB spokesperson Ryan Bird.

"We would encourage anyone that has concerns about the content to contact the site administrator to make them aware and should they be experiencing any difficulties as a result of posts, to speak with staff at their school such as a teacher, guidance counsellor or principal."

The site claims to have 28,000 subscribers and is populated by submissions from teens. It posts photos and full names of teens allegedly associated with the gossip.

Last week, the site advertised the "Rosedale Jam," which took place Saturday in Rosedale Park and where police allege the swarmings, assaults and robberies took place.

In a subsequent post, the gossip site named people it claims were victims.

Police said that they believe there are several unreported incidents and are asking the public to contact them if they have any information.