A man threatened a 56-year-old woman and tried to steal her handbag after watching her withdraw money from a supermarket cash point in High Wycombe.

The victim told officers that she had noticed a man and woman watching her as she withdrew cash from Morrisons in Temple End on Saturday and was then approached by the man as she went to get in her car.

At around 6.45pm he grabbed the shoulder strap of her handbag and demanded she gave him the bag and said he had a knife.

The victim screamed and the man ran off without the bag.

The man is described as white, in his late teens, slim, with fair hair and a goatee beard. He was wearing a light grey tracksuit with the hood up. He was also carrying a black bag.

The woman is white, in her late teens, short, stocky with dark brown hair tied back in a bun. She was wearing a pink tracksuit top and dark-coloured trousers.

Designated Investigator Victoria Humphreys said: “I would ask anyone with information about this incident to contact the police on 101.

“I would like to reassure the community that this is being investigated thoroughly and this is an isolated incident.”

If you have information and want to speak to officers anonymously, contact Crimestoppers on 0800 555 111 or online at www.crimestoppers-org.uk