One student was killed and two others were wounded in a stabbing outside their Southern California high school, authorities said.

The students were attacked in front of Santa Ana High School at about 3:25 p.m. Wednesday, shortly after dismissal, according to school officials and police in Santa Ana, which is about 30 miles southeast of Los Angeles.

When the victims were taken to hospitals, one was in critical condition and two were in stable condition, police said. The student in critical condition later died, police said.

The attack appeared to be gang-related, Santa Ana police spokesperson Natalie Garcia told reporters.

Police are searching for the two unidentified suspects, Garcia said. It’s not clear if the suspects attend Santa Ana High School or another school, she said.

“Our thoughts are with the family of the student who passed, and with all those impacted by this senseless act of violence,” the Santa Ana Unified School District said in a statement.

“Out of an abundance of caution, there will be an increased presence of Santa Ana School Police on and around Santa Ana HS on Thursday,” the district added.