In this still image taken from footage provided by KEYT-TV, a crowd confronts police during a weekend college party in Isla Vista, Southern California. Picture: KEYT-TV

Isla Vista, California

About 100 people were arrested and at least 44 people were taken to the hospital during a weekend college party in Southern California that devolved into a rock- and bottle-throwing melee, authorities said.

The violence broke out in the densely populated beachside community of Isla Vista at 9.30pm on Saturday during the annual spring break party known as Deltopia, the Santa Barbara County Sheriff's Office said.

Sheriff's spokeswoman Kelly Hoover said things escalated after a University of California, Santa Barbara police officer was hit in the face with a backpack filled with large bottles of alcohol.

Authorities said some members of the crowd of 15 000 then began throwing rocks, bricks and bottles at officers, lighting fires and damaging law enforcement vehicles.

“It was an emergency situation where we had to call in mutual aid,” Hoover said. “They have had civil disturbances before in Isla Vista, but it has been many years since something like this.”

Authorities reported using teargas, pepper spray and foam projectiles to disperse the surging crowd.

At least five more officers were injured in the melee, including one officer who was hit in the face with a brick and two others who were both hit in the hand with bottles, sheriff's deputies said.

It was not immediately known on Sunday how many people remain in custody or were still being treated at the hospital.

Earlier on Saturday, authorities also responded to reports of a stabbing and found several individuals carrying weapons, she said. Aside from those who were treated after the brawl broke out, nearly every person who was hospitalised on Saturday had consumed excess alcohol, Hoover added.

“It really was ridiculous,” Hoover said. “Deltopia attracts out-of-towners who come in and are not invested in our community and there are some who come to cause trouble.”

The situation had stabilised by Sunday morning after sheriffs received support from multiple agencies in neighbouring Ventura County.

Isla Vista borders the university and is known for partying. The area has roughly 23 000 residents, of which 60 percent are students. - Sapa-AP