A teenager is in critical condition after a freak accident during after-school sports training.

A 13-year-old boy was hit in the head during hammer throwing training. at St Albans Reserve in Clearview in Adelaide’s north at about 5pm on Thursday.

The ambulance crew treated the boy, who suffered a serious head injury, and he was taken to the Women’s and Children’s Hospital, where he is currently fighting for his life.

It is known that the boy was a graduate of Christian Brothers College.

Police spent several hours at the scene on Thursday evening, where they spoke to another student at the school.

The boy, 13, was seriously injured during a hammer throw training session at St Albans Reserve in Adelaide’s north on Thursday. The scene is pictured

Police spent several hours at the scene on Thursday evening talking to witnesses.

According to The Advertiser, several employees of Christian Brothers College were present at the scene but did not want to comment on the incident.

Enfield Harriers Sports Club is based on the reserve which is located Hammer throwing circle.

It is known that the club has implemented a list of safety rules for hammer throwing.

Daily Mail Australia has contacted the school for comment.