A nine-year-old pupil caused alarm when he brought a knife into his primary school.

The boy was excluded and the police involved after the blade was seen at Riverview Junior School in Gravesend on Tuesday.

The police were called and the Year 5 pupil was sent home on the advice of officers.

The school has since sent a letter home to parents to explain action taken "to address this pupil's behaviour and to ensure the safety of other children".

In the letter, head of school Pamela Wenban said: "Many of you will be aware that we had a serious incident in school on Tuesday, involving a year 5 pupil who had brought a knife into school."

Police say they are continuing to provide support and advice ahead of the child's return to class tomorrow.

"Please rest assured that, as always, the safety and wellbeing of your children is our highest priority" - Head of school Pamela Wenban

But he remains barred from the playground and dining hall until the school are confident there is no risk to other children.

The letter says the child has "robust parental support" and a previous record of good behaviour.

It adds: "The pupil concerned, and his parents, understand the seriousness of what he did and we are confident that this was an isolated incident, which will not recur.

"Please rest assured that, as always, the safety and wellbeing of your children is our highest priority."

A police spokesman said: "Kent Police received a report of a pupil bringing a knife into Riverview Junior School, in Cimba Road, Gravesend, on Tuesday 8 December.

"An officer attended on the day and provided advice to the school. An officer will also visit the school today to provide further support."

Kent County Council played down the incident and criticised parents for posting "inappropriate comments" on social media.

“Despite the apparent seriousness of this incident, this was simply an action by a nine-year-old boy who did not realise the full implications of what he was doing," said a KCC spokesman.

“Prior to this incident, his behaviour record was exemplary and his parents are distraught about what has happened and are very supportive of the school.

“We are satisfied that the school has taken the appropriate disciplinary action."

”However, it is extremely unfortunate that some parents have used social media to post what we deem to be inappropriate comments. In these cases we are supporting the school to ensure action is taken and where appropriate the matter is being referred to the police.”

The school has also been contacted for comment.