An au pair was threatened with a carving knife and robbed of her purse.

The 21-year-old from the Czech Republic was walking with friends in Montpelier Road, Brighton, when the hooded mugger approached.

He first put the knife to the throat of a friend who escaped and ran into the road to hail a passing taxi driver for help.

The robber then threatened the au pair who handed over her purse containing a small amount of cash.

She was badly shaken but otherwise unhurt.

The attack happened on Saturday, November 23, and has just been reported to police.

Detectives appealed to the taxi driver and other witnesses to come forward.

The robber was 25 to 30 with short black hair. He wore a balaclava and dark clothing.

He and an accomplice were of Arabic or Mediterranean appearance.

Anyone with information should contact Detective Constable Duncan Chalmers on 0845 6070999.