A woman was robbed at knifepoint in Florence Road, Brighton, at about 2am yesterday (Sunday 7 August).
The 19-year-old local victim was approached from behind by a man and threatened with a knife.
He stole her distinctive red bag, embroidered with golden elephants, and its contents.
The man told the victim to run up Florence Road towards Southdown Avenue while he ran off towards Beaconsfield Villas.
Detective Constable Steve Amner said: “The victim has understandably been left shaken by her ordeal.
“Detectives are investigating this serious offence and are keen to speak to anyone who was in the area at the time and witnessed any suspicious behaviour.”
The suspect is described as 6ft tall slim-built white man with a shaven head.
He was wearing a loose fitting blue-grey hoodie and black trousers.
Anyone with information is asked to contact Sussex Police on 0845 6070999 or the independent charity Crimestoppers anonymously on 0800 555111.