An 11-year-old girl foiled an attempt to abduct her as she made her way home from school.
The girl was walking home along the A1198 at Bassingbourn at 1550 BST on Monday when she was stopped by a man driving a new-style blue Mini.
The driver tried to pull her into his car, but she managed to break free.
She ran home and told her parents what had happened.
Detectives were due to interview the girl about the incident on Tuesday.
Very serious
Cambridgeshire Police said the incident was very serious and is alerting local schools to the attempt.
The man is described as white, around 18 to 19 years old, about 5 ft 10 ins tall, and clean-shaven.
He was wearing a blue hooded top and black tracksuit bottoms.
He is thought to have had a blond, spiky quiff and was accompanied by a passenger.
Anyone with information is asked to contact Cambridgeshire Police.