Police are investigating multiple incidents at a massive student Halloween party in Quebec, where three sexual assaults were reported and 12 young partygoers were taken to hospital with drug or alcohol-related illnesses.

The alleged incidents happened Friday at the Mont Cascades ski resort in Cantley, Que., during an event called “Spookland” with about 1,000 students in attendance, police said.

Police say they have received at least three reports of sexual assault from people who attended the event. Another 12 people – almost all of them minors – were taken to hospital with possible cases of drug or alcohol poisoning.

Investigators are also looking into allegations made by girls and young women that they were under the influence of a date-rape drug.

Police said in one case, a 16-year-old girl was found with no clothes on and unconscious. She had GHB (gamma-Hydroxybutyric acid), commonly known as the date rape drug, in her system.

The Spookland party’s website says the event was for students aged 16 to 21, with a licensed area for people over the age of 18. Partygoers were brought in by bus from a number of Ottawa-area schools.

However, a number of partygoers told CTV Ottawa that kids as young as 14 were at the party. They also reported seeing people vomiting, fighting and doing drugs. Others reported fighting and drinking on the buses, and said the venue was difficult to get into because it was overcrowded. Still more people were reportedly passed out.

Police said some partygoers had to be kicked out of the event because the ski resort was over its maximum capacity.

Paramedics and firefighters also reportedly answered calls at the scene.

Spookland organizers said they called onsite paramedics to deal with partygoers who needed attention.

Event organizers told CTV Ottawa that police were alerted to the party plans ahead of time and partygoers were thoroughly screened at the door for anything deemed “inappropriate.”

“We regret any perception and misinformation that we, in any way, tolerated contravention of the rules of our zero-tolerance policy on underage drinking and no drugs or paraphernalia,” organizers from ‘I’m With the DJ’ told CTV Ottawa in a statement Saturday.

"We are cooperating with the police in every possible way," said the statement. "We have also begun an internal review of this matter."

Police said they will release further details about the investigation on Monday. Officials are asking anyone with information to contact police.