"Deltopia," an annual spring break celebration near the University of California at Santa Barbara, turned into a riot last night with over 100 arrests by police dressed in riot gear.

Officers fired tear gas into crowds of students who set fires and smashed cars, including police vehicles, reported CBS Los Angeles (video below).

It took several hours for Santa Barbara, Calif. police to disperse high school and college students, who numbered at 15,000.

Six police officers were injured, including one officer who was hit by a backpack filled with bottles of booze.

The street party turned into a riot after police responded to some stabbings, reports ABC 7.

“Chemical agents and less lethal foam projectiles were deployed to disperse the crowds,” Santa Barbara police said in a statement.

Sources: CBS Los Angeles and ABC 7