Two masked raiders armed with knives last night took the tally of armed robberies in Worthing to 15 since Christmas.

The raiders held up staff and customers at the Mace store in Aldsworth Parade, Goring.

They bundled them into a back room, raided the till and escaped with cash, phone cards, lottery scratchcards and cigarettes.

It was the latest in a string of armed raids at Worthing shops and garages. There has also been one unarmed robbery.

Nine of the raids are thought to be the work of one man, who uses a shotgun. Yesterday's is believed to be unconnected.

The pair who robbed Mace at 8pm were black, in their late 20s or 30s, about 6ft tall, heavily built and wore balaclavas and dark clothing.

Gary Shapland, chairman of the town centre problem-solving group and vice-president of the Chamber of Trade and Commerce, said: "It is obviously frustrating for the business community because the police don't know where to be at any one time.

"These raids appear to be quite random, from one end of town to another and at all times of day.

"To date no one has been hurt but as time goes on there's always the fear that someone is going to get seriously injured.

"I have never heard of robberies on this extreme level happening in Worthing before. The important thing is to catch these people and put a stop to it before anything terrible happens."

Police believe copycat raiders have started targeting shops and betting offices.

Anyone offered cheap phone cards or lottery tickets is asked to call Detective Constable Philip Lankshear of Worthing CID on 0845 6070999.