Fort Collins police say they used tear gas to disperse a large and noisy street party near the Colorado State University campus as some revelers threw bottles at officers.
Police spokeswoman Rita Davis says officers were called to the Summerhill neighborhood late Saturday night amid complaints of a gathering that drew about 300 partygoers.
She says in a news release that officers urged people to leave, but the crowd became unruly and began throwing bottles at police as well as climbing on cars, street light poles and trees.
Some media reports described the melee as riot-like.
Davis says that eventually, police used tear gas and pepper spray to disperse the crowd.
Three partygoers were treated at a hospital for minor injuries, but Davis says no officers were hurt.
The media reports say the event drew mainly a college-age crowd after it was advertised during the week via social media.