DURHAM, N.C. (WNCN) — A student resource officer at a Durham high school was hit in the head with a metal bottle while breaking up a fight last week, according to documents.

On April 14, the school resource officer at Riverside High School — a sergeant with the Durham County Sheriff’s Office — was walking the halls during class change before 2:30 p.m. when she noticed a crowd.

The sergeant made her way through the crowd and came upon a fight between two students. She helped one of the involved students to be moved to safety before approaching the other student, according to a report.

The second student threw an aluminum bottle filled with water at the SRO as the deputy approached her.

The bottle hit the SRO in the forehead – causing swelling and bleeding.

The SRO was taken to the hospital by EMS for treatment of a mild concussion, according to the report. The injured deputy has suffered symptoms of a concussion and swelling and bruising around her eye.

She is out of work until she recovers.

Both students involved in the fight have been expelled and a juvenile petition has been filed against the student who threw the water bottle.

The sheriff’s office said it could not discuss the incident due to the age of the students involved, other than saying “There was an incident at Riverside where an SRO was struck with an object while attempting to break up a fight.”