POLICE are hunting two robbers, one of whom wore an "old man" rubber mask in a hold-up at a bookies.

Two men brandished a knife and a screwdriver and got away with an undisclosed sum of cash at Ladbrokes, in Market Street, Gainsborough.

They entered the premises by the back door and ran along Spital Terrace, into North Street car park, where they made off in a blue car.

A knife was recovered at the bookmakers.

Lincolnshire Police said staff were not injured, but were shaken.

Force spokesman Dick Holmes said both men hid their faces with masks, but the man brandishing a black-handled knife wore a very distinctive one.

He said: "The man with the knife had a rubber mask over his face, the sort of thing you'd get from a joke shop.

"It is possible that this may have been disposed of by the side of a road on the way out of Gainsborough or in a bin, so we would be interested in hearing from anyone who makes such a discovery.

"We have traced the blue Citroen Berlingo estate car, which it is believed they used to get away to an address in Humberside, but the vehicle is unconnected.

"It was a very frightening experience for staff who are shaken by their ordeal, but thankfully not injured.

"Officers are studying CCTV and we would like to hear from members of the public who saw anything of the incident or anything suspicious in the hours beforehand or even the days leading to the incident."

The robbery happened at about 5.40pm on Sunday.

The first of the offenders is described as 5ft 6ins to 5ft 7ins, slim, with broad shoulders.

He was wearing a rubber "old man" style mask, a burgundy waterproof jacket, dark tracksuit bottoms, white trainers and gloves.

The other robber is said to be 5ft 8ins to 5ft 9ins and of larger build than the other man.

He wore a navy blue hooded top with green and purple writing on it and Adidas tracksuit bottoms.

He also wore gloves and was carrying a yellow handled screwdriver.

Ladbrokes spokesman Nick Weinberg said: "As always, the safety of customers and staff remains our priority."

Call Lincolnshire Police on 0300 1110300 or Crimestoppers anonymously on 0800 555111.