A 15-year-old girl is in hospital with serious injuries after she was lit on fire at a Saskatoon high school, police said Thursday.

Sgt. Ken Kane told reporters that a school resource officer, who was at Evan Hardy Collegiate for a different matter, apprehended a 14-year-old girl as a suspect.

He did not say how the victim was lit on fire or the extent of her burn injuries.

鈥淥ur officer that was on scene was at the immediate area of the event within 30 seconds and had someone in custody within 60 seconds,鈥� he said.

鈥淚 believe this situation could have been much worse and more out of control if we didn鈥檛 have an officer there right away.鈥�

Kane said school staff members extinguished the fire and one teacher who was injured also went to hospital.

Saskatoon Public Schools said more than one staff member was hurt. It said the suspect is also a student.

The school was closed for the rest of the day, and classes were cancelled for Friday.

鈥淭his incident resulted in serious injuries to the student and to the staff members that intervened. The injured persons were transported to hospital,鈥� a school division spokesperson said in an emailed statement.

鈥淲e are grateful to the Evan Hardy staff for their immediate response and acknowledge it was a traumatic incident for the entire school community. We are providing supports to students and staff.鈥�

Kane said the attack was upsetting for officers.

鈥淭he mood in our office right now is quite low,鈥� he said. 鈥淭his is not something we ever expected and really could prepare for.鈥�