Leigh Academy in Dartford was on lockdown today because a man acted in a 'threatening manner'.

Officers told teachers to keep pupils inside the school building in Green Street Green Road after the man, who is known to the school, was spotted.

Police have now revealed the reason for the lockdown.

A spokesman said: "At approximately 9am today a man attended Leigh Academy in Dartford and acted in a threatening manner.

"An officer, who happened to be attending the school, spoke to the man and words of advice were given.

"As a result of the incident, the academy made a decision to keep the children in the school during the lunchtime break."

This evening the Leigh Academies Trust released a statement revealing a bit more information.

Spokesman Richard Taylor said: "This morning in response to a non-specific threat, made by an individual known to the academy, in consultation with police we decided to temporarily restrict students from leaving the grounds at lunch time as a precautionary measure.

"As usual in these situations, student safety is our ultimate concern and we felt it best to take this action even though the threat was non-specific.

"Students were immediately informed and lunch was provided for any sixth-form students that would normally obtain food offsite.

"We have remained in regular contact with the police throughout the day and they have advised us that no further action is necessary."

Mr Taylor said earlier students would be released from school as normal at the end of the day and there was no need for them to be collected early.

He added: "We are expecting to return to a normal school day tomorrow but if parents have any specific concerns they are welcome to contact the school to discuss them."

A message on the school website said: "Following advice from police we have made a decision to keep all students inside of the academy grounds today as a matter of precaution.

"The school day is unaffected and will finish at the usual time."