A passerby heard a group of young people yelling and called authorities, and the girls were subsequently taken to hospital.
Police are questioning them on the possibility that they were sexually assaulted, spokesperson Const. Danny Richer said.
"On the scene police officers discovered two young women age under 18 years old. And some evidence found on the place could have made police officers think that there was maybe sexual acts in the park," Richer said.
He said the girls were found intoxicated and alone, and the others involved fled the scene before authorities arrived. Police are looking for those other people, who authorities believe knew the girls.
According to authorities, there would have been 10 to 15 people in the park at the time.
Police say they questioned a teenaged boy and released him.Borough Mayor Chantal Rouleau said more the borough will focus on keeping the park safe to prevent anything like this from happening again.