Students at a private school for teens with privileged backgrounds pelted police officers with rocks and sticks during a riot on the campus here Saturday.

Six students were taken into custody after allegedly assaulting Heritage School staff and law officials who responded to a 911 call at 2:10 p.m.Police did not release the names of the juvenile suspects.

School officials called police to help stop the melee that started inside the school and eventually spilled onto an outside porch. Police were told several students were upset at the school's staff and became belligerent.

Investigators still do not know exactly what sparked the campus riot, said Provo Police Capt. Keith Teuscher. An investigation is planned to pinpoint the cause.

"Apparently, the kids became unruly," he said. "They weren't following the rules and it went from bad to worse."

Provo Police Sgt. T.K. Meyer said the uproar had reached a fever pitch when police from Orem and Provo arrived.

"The campus was chaotic," he said. No estimates were available for damage to school property.

Meyer said police chased two male students who ran when they saw the police cars pull up to the Provo school, 5600 N. 450 West. The two boys also reportedly assaulted police before being taken into custody a few blocks from the campus.

Orem police officer Randy Clements was treated for minor injuries by paramedics at the scene after being hit with a rock on the back of the head.

He was smacked while wrestling the teenagers who fled the scene. The teens also attempted to pry Clements' gun from his holster during the altercation, said Orem Police Lt. Bob Conner.

"He had a good-sized bump on his head," Conner said. "It really dinged him."

About 130 students between 12 and 18 attend the school for scholastic and disciplinary reasons. A treatment center is at the same address.

Jerry Spanos, the founder and director of the 14-year-old school, did not immediately return Deseret News phone calls for comment.