Police are holding a teacher on suspicion of seriously assaulting a 14-year-old boy at school.

The boy received a serious head injury after allegedly being attacked by a male teacher at All Saints' Roman Catholic School in Mansfield, Nottinghamshire. He was transferred for specialist treatment after his condition deteriorated during the afternoon.

Nottinghamshire police said the incident happened just after 11am yesterday. The unnamed youngster was taken to Kings Mill hospital in Mansfield but was transferred to the Queen's Medical Centre in Nottingham. His family have asked for privacy, the police said.

A spokeswoman for the force said a 49-year-old man was arrested and remained in police custody.

"The police investigation is being led by Detective Superintendent Adrian Pearson, with specialist officers from the public protection unit. They are working with the headteacher and staff at All Saints' Roman Catholic School."