Pupils have been urged to walk to and from their school in groups amid fears one child was inappropriately approached by a stranger.
Police are said to be investigating the incident near Hebburn Comprehensive School, in Campbell Park Road, on Monday morning.
Headteacher David Thompson said in a letter to families dated Monday: "Following an incident in the Campbell Park Road area this morning in which one of our pupils was inappropriately approached by a member of the public, pupils and parents are asked to be vigilant and to report immediately any inappropriate behaviour to a member of staff in school or to the police.
"I am not at liberty to give any further information, as the police are still investigating the incident.
"Whilst police investigations are ongoing, it would be sensible for pupils to walk to and from school in groups of two or three, where possible. If children are staying back after school, you may wish to make arrangements to collect your son/daughter.
"I am not wanting to cause alarm, but the safety of our pupils is of paramount importance."
Further information about the incident is expected to be released by Northumbria Police on Wednesday.