PUPILS at four primary schools in north Abingdon have been warned to be on their guard after two incidents in which a man wearing a black balaclava chased children.

No one was hurt but worried parents are keeping a more careful watch on their children and the police are working closely with the schools to trace the man.

In the first incident, on May 22, a nine-year-old girl from Dunmore Junior School was cycling home along a path near Boulter Drive and Alexander Close when a man wearing a balaclava and gloves appeared from behind a bush and chased her.

The frightened girl managed to cycle away and told her parents, who reported the incident to the police and school. The girl described the man as Asian. He was wearing a blue knitted jumper, black tracksuit, white trainers and a rucksack.

In another incident, 19 days later, two boys from St Nicolas School were playing in Boxhill Woods when they were confronted by a man wearing a balaclava. They ran off and the incident was reported to the police.

The man was described as aged between 30 and 40, with brown eyes and dark clothing.

Police believe the same person may have been involved on both occasions.

After the May incident, the acting headteacher of Dunmore, Martin Lester, sent out a letter to parents which said: "I am writing to alert you, but hopefully not alarm you, following an incident. Fortunately, no physical harm was inflicted. At this stage we are not sure whether this was a silly prank or something potentially more serious."

Dick Furniss, the head of St Nicolas, also sent a letter telling parents that he did not wish to alarm anyone, but felt it important that parents were "particularly vigilant".

Parents of children at Dunmore Infants School and Long Furlong Primary School have been told of the incidents.

The heads of all four schools were not available for comment, but county council education spokesman John Mitchell said: "Both these incidents are disturbing, but fortunately no harm has come to the children. Letters have been sent out to parents. In school assemblies children have been reminded not to have anything to do with adults they don't know and to be on their guard."

Denise Kennedy has two children at Dunmore Infants and one at Long Furlong. She said: "Naturally there is a lot of concern among most parents about these incidents. Parents are keeping a much closer eye on their children when they go to school and out to play. We are being more vigilant. You can't take any chances."

The Thames Valley police schools liaison officer for the Abingdon area, PC Steve Pedley, is investigating the incidents and has been working closely with schools in the town.