A Kalani High School student is in serious condition after being stabbed on campus and another student has been arrested.

Principal Gerald Teramae said the incident happened about 8:50 a.m. this morning in a math class in the school's E building. About 30 students were in the classroom at the time.

Teramae said a 17-year-old was detained until police arrived.

Honolulu police said both students are boys.

They said the victim, 16, was stabbed multiple times in the torso with what was described as a large knife.

Police said there was no prior instance of violence between the two.

Teramae said the school was placed on lockdown until 10:45.

He said the students in the classroom at the time of the attack were kept in a gym to be interviewed by police, and their parents were notified.

Counseling will be offered to students who need it, Teramae said.

Teramae said it is unclear what might have led to the attack. He said there rarely are fights at Kalani.