Masked men armed with knives threatened staff at Valerie's chippy, in Walter Thomas Street, Southwick, at 9.30pm yesterday, demanding they hand over the takings.

But workers refused to hand over the cash, and the failed robbers fled, chased by people who had been in the shop.

The men were followed to a nearby street where it was thought they were hiding out in a house.

Police were called and sealed off the property.

More officers armed with tasers were then drafted in but the stun-guns were not used.

Officers carried out a full search of the house, but the men could not be found.

But a knife, which is believed to have been discarded by one of men, was found in a drain in a nearby street and sent for forensic examination.

Police are still hunting the two men involved in the incident. The robbery is now being dealt with by Southwick CID.

Further investigations were due to be carried out today.

A spokesman for Northumbria Police said. "Nobody was injured in the incident, and any witnesses who have not already been spoken to by police are asked to contact us on 08456 043 043."

Last night's incident was latest raid on businesses across Wearside – with bookies and takeaways being the main targets.

Masked men armed with hammers robbed the Fry Fry chip shop on Aline Street, Silksworth, last Sunday, and several bookmakers in the city have been hit in recent months.

Police have made a number of arrests in relation to these robberies, and this week claimed they are mainly opportunist crimes.