Terrified staff had a gun pointed at them during the fourth armed robbery in weeks at bookmakers in the Bradford district.

Detectives today urged bookies to make personal security a priority after the worrying increase in armed raids.

A male and a female employee of the Ladbrokes shop in Stonehall Road, Eccleshill, Bradford, were left shocked after four masked men threatened them with a handgun and an axe after bursting into the premises at 7.25pm on Monday.

They forced the staff to hand over an amount of cash from the till and a safe before fleeing at high speed in a waiting dark Volkswagen Golf with its lights off.

Detective Inspector Noel Devine, of Bradford North CID, who is investigating the robbery, said: "Premises that carry money are always going to be vulnerable to desperate people.

"Any offence like this is worrying, especially when firearms are brandished. The worry is what might happen if something goes wrong and people with weapons start to panic. That is when people can get injured."

But Det Insp Devine said he did not feel there was a new trend towards robbing bookies. "These incidents are still a very rare occurrence and our initial inquiries do not suggest there is a team operating in the area. We review every offence of this nature to look for links, but this looks to be an isolated incident.

"Business premises with money, which could be targeted, should be aware of personal safety and make suitable security arrangements. But the betting industry is aware of security and it is an ongoing issue with them."

The Ladbrokes raid follows evening-time armed robberies at Coral's in Allerton Road, Allerton, on November 20; William Hill's in Crag Road, Windhill, Shipley, eight days later; and Coral's in Huddersfield Road, Low Moor, on December 19.

The raiders carried firearms in the first incident; a young female cashier was forced to hand over money at gunpoint in the second incident and a masked gang-of-three, armed with an axe, crossbow and baseball bat threatened staff in the Low Moor robbery.

Russ Phillips, deputy chief executive of the Association of British Bookmakers, said bookmakers were sometimes targeted by robbers acting under the "misconception" that they were rich pickings.

He said: "Some robbers do not seem to understand the measures that bookmakers have taken to reduce the cash available on site. Robbers frequently leave with less than £1,000."

Mr Phillips said his organisation offered a reward of up to £10,000 for information leading to the arrest of robbers who raided bookmakers shops.

"We have made significant pay-outs over the last year under this scheme and we are keen it is known about locally and people use it by ringing the local police or by using Crimestoppers, who we have an agreement with," said Mr Phillips.

Since last September, the Gambling Act has allowed bookmakers' shops to open into the evening in winter, as opposed to the old rule which meant they could only open late during the summer racing months.

Mr Phillips said: "It's too early to see if there is a link between the longer opening in winter and the number of robberies.

"You often get a gang which is responsible for a spree and that might be what is happening in Bradford at the moment. But once that gang is pursued and detained, you might see the robberies reduce just as quickly as they appeared."

The robbers in the latest incident were all white and wore balaclavas and dark clothing.

Police are keen to trace a driving instructor who took down the details of the fleeing car and alerted bookies staff.

Anyone with information is asked to contact Det Insp Devine on 0845 6060606.

e-mail: steve.wright @bradford.newsquest.co.uk