A science teacher arrested after a schoolboy was left with serious head injuries is being held on suspicion of attempted murder.

Peter Harvey is also being questioned about alleged assaults on two other pupils during the same incident at All Saints' Roman Catholic School in Mansfield, Nottinghamshire, on Wednesday.

Officers were called to the school after paramedics arrived to find the 14-year-old pupil in a pool of blood at the entrance to a classroom in the science block.

Nottinghamshire Police confirmed that a weapon was used in the attack.

Parents at the school gates yesterday morning said the 14-year-old was allegedly hit with a weight.

The boy was taken to a local hospital but his condition deteriorated and he was transferred to a specialist unit at the Queen's Medical Centre in Nottingham later on Wednesday.

Nottinghamshire County Council, the local education authority, said the boy's condition "slightly improved" overnight.

Police said that the two other children who were injured in the same alleged attack were well enough to return home on Wednesday night.

Officers refused to say whether the boy and girl, both 14, had leapt to their classmate's defence.

The Year 8 class was having a science lesson when it appears a row erupted between the boy and the teacher. It is alleged the assault then took place.

The blood-spattered classroom was forensically examined by officers and has reopened, although it is understood lessons are not being taught there.

Detective superintendent Adrian Pearson said: "Obviously the whole class is traumatised by what has happened.

"People send their children here from great distances because of its academic record, and what happened is very much out of character for the school.

"I know a number of parents have rung the head-teacher about what has happened but I would appeal for everyone to be calm, particularly in relation to those people involved."

Mr Pearson said a dedicated team of 12 officers was questioning students in the class with their parents present.

He added: "The school, the teachers and the parents are absolutely shocked. It was a trauma to all those involved."

Police have been given a further 12 hours to question Mr Harvey and it is expected that they will require further time after that.