VANCOUVER - RCMP say 19 students from the University of British Columbia are facing charges including assaulting a police officer, resisting arrest and obstruction of a police offer after a peaceful campus protest turned wild Friday night.

Police say they were called to UBC to assist the fire department and campus security after one student obstructed officials from extinguishing a bonfire.

The incident turned into a standoff when a student leader was handcuffed and detained, and dozens of students surrounded the police vehicle to block its departure.

Student Justin MacElroy witnessed the conflict.

"The students refused to let them hose it down," he said. "They put their foot down on the water and that's when things started to escalate."

The students remain in custody but have not been formally charged.

According to a release from organizers Students for a Democratic Society and Trek Park for People, the student was approached by police and was told she violated a bylaw for blocking the fire department from access to a hose.

An officer threw her to the ground, the students' release says, and pushed her face into a puddle of mud, and when another student questioned the officer, he was arrested.

Police say two officers were assaulted by students after UBC campus security called other police detachments for backup, including the UBC, Vancouver and Richmond Police.

Police credit the co-ordinated efforts of the three police detachments with eventually extinguishing the fire.

Video footage shows police arresting and dragging protesters from the scene.

UBC student Steven Klein told CTV News the protest began as a peaceful rally against development of the nearby grassy knoll, a popular student hangout, into an underground bus loop.

"This was a musical event about the ongoing development of this part of campus," he said.

"Towards the end of the night a bonfire was started, the situation got slightly out of hand, they put out the bonfire, there were people who stepped in front of the hose."

Knoll Aid 2.0 was part of a larger campaign against the development and commercialization of campus, according to a statement released by an anonymous student.

The student called police "highly aggressive and belligerent," and accused the police committing gross abuses of power, and called on UBC administration to defend its students' rights.

With a report from CTV British Columbia's Shannon Paterson