Detectives are today stepping up the hunt for two women who armed themselves with kitchen knives to rob a terrified garage cashier.

The women, who wore stockings over their heads, escaped with an undisclosed amount of cash from the till of a 24 hour petrol station.

Today a spokesman for the Regis Service Station in Chichester Road, Bognor, said no one was available to discuss the raid, which happened just after 4am on Wednesday.

But a detective said: "It is unusual for two women to carry out a robbery like this but perhaps it shows the change in society and that women can be as involved in crime in the same way as men."

The garage, which is on the busy A259 between Bognor and Chichester, was also robbed last month but the offender was a lone male.

Police say the two women brandished kitchen knives as they walked into the payment and mini-supermarket area of the petrol station.

Western division spokesman David Ward said: "Both were wearing stockings over their heads when they went into the garage at 4.10am.

"One woman climbed over the counter and took a sum of cash. The male cashier was threatened with a knife but did not suffer any physical injury."

The women then ran out of the shop but police have not yet established whether they escaped in a vehicle.

One of the raiders was described as in her early 20s with blonde hair and about 5ft 5in tall. Her build was described as a medium and she was dressed in a dark-blue, long-sleeved jumper over a white top, dark trousers and white trainers.

Her accomplice was thought to be about the same age but with dark hair. She wore a dark jacket and trousers and carried a blue rucksack.

Police are still searching for a man in his 30s who walked into the same service station at 2am on June 11 and threatened a cashier.

The robber, who wore a latex mask over his face, escaped with an estimated £255 from the till.

Detectives say anyone with information about the latest robbery should call detectives at Bognor on 0845 6070999 or Crimestoppers on 0800 555111.