A robber pressed a knife to a sales assistant's back and demanded cash in a raid on a convenience store in Henfield.

The man, who wore a scarf over his face, marched student Simon Price to the till after walking into Dillons in High Street.

Mr Price, 19, an advanced business student who works part-time at the store, was confronted by the knifeman when he returned from putting the rubbish out.

The robber, armed with a kitchen knife, ordered him to open the till.

Two other members of staff were working in a back room but the raider was in and out before they could react.

Mr Price said: "It was pretty scary but I didn't really think about it at the time. It was only afterwards I felt the shock.

"I was pretty shaken. I acted coolly while he was in the shop and I didn't care what he took, so long as everybody was OK."

The robber got away with up to 70 boxes of Benson & Hedges and Mayfair cigarettes and made Mr Price open the till before escaping.

The man was white, 6ft 1in tall, of medium build and had a large, bony nose.

He wore a white jacket with a hood, a black scarf and white trainers.

Police are scanning security camera footage to produce a photographic image of the robber, who struck shortly before 10.40pm on Wednesday.

Anyone with information about the raid should call Steyning CID on 0845 6070999.