A large, rowdy party at Western Washington University turned into an "out-and-out riot" in Bellingham, Wash., Saturday night, police told NBC News.

According to the Associated Press, “Hundreds of college-aged revelers — thwarted in efforts to continue a large party – threw projectiles at police who responded with pepper spray to disperse them.” Fox News noted Police Sgt. Mike Scanlon confirmed that there were multiple arrests during the melee late Saturday and early Sunday.

In Scanlon's words, “The intoxicated crowd turned into pretty much an out-and-out riot.” The riots began when police broke up a large party and revelers then moved, to a nearby park where more people joined them, eventually turning into a 500-person melee.

Scanlon says that as police tried to clear the park, the crowd began hurling projectiles at authorities. The police then responded by using pepper spray on the crowd and cleared the area after around 45 minutes. The Washington Post reports that the number of arrests in currently unknown as is the knowledge of any injuries that may have occurred during the riot.