An 18-year-old woman was mugged at knife point for her iPhone in Rickmansworth Road, Watford.

The victim was approached by a teenage boy who produced a knife and demanded she hand over her iPhone 5, which she did before he ran off towards the High Street at around 7.10pm on Sunday, December 21.

Police are appealing for information and witnesses, particularly two women who stopped to assist the victim, following a robbery.

The victim was not injured during the incident.

The suspect is described as a white male aged around 16 years old who was of a slim build and between 5ft 6ins and 5ft 9ins tall. He had short brown/black hair and was dressed in all dark clothing.

Detective Constable Jennifer Stoddart said: "Two women who had been on their way to the Colloseum stopped to help the victim and I would ask that these ladies please contact me as they may have vital information as part of the investigation.

"I am also keen to hear from anyone else who has any information which could assist."

Anyone who can help should contact DC Stoddart on 01923 472985 or via the Herts Police non-emergency number 101 quoting crime reference number C1/14/6096.

Alternatively contact Crimestoppers anonymously on 0800 555 111.