SANTA ROSA, Calif. — An 18-year-old has been injured and three teen boys have been arrested after a stabbing outside a Santa Rosa middle school.

The Santa Rosa Press Democrat reports ( ) that the one 14-year-old and two 15-year-olds were taken to juvenile hall Saturday night following the afternoon stabbing and booked on suspicion of assault with a deadly weapon causing great bodily injury and gang charges.

Sonoma County Sheriff’s Sgt. Spencer Crum says the boys were playing basketball when they encountered the 18-year-old. Crum says investigators believe the boys and the man were affiliated with rival gangs.

The boys then contacted an adult who drove them off the middle school campus. They were later arrested at a grocery store.

Information from: The Santa Rosa Press Democrat,