Armed robbers stole thousands of pounds in a dawn ambush at an Oxford bank in a mirror image of a raid in Abingdon three weeks ago.

Shopkeepers have voiced concern at today's attack, which happened at the Abbey, in Banbury Road, Summertown.

Police said four masked men armed with hand guns stole thousands of pounds from Group 4 Securicor guards inside the bank at 5.30am.

One of the guards was hit over the head with the handle of a gun. He was taken to hospital for treatment of minor injuries.

Acting Det Insp Kevin Elkins, of Oxford CID, said: "The men were armed with what is believed to be hand guns, but no shots were fired."

Police are now investigating possible links with an identical raid at the Abbey's Abingdon branch on Friday, October 26.

On that occasion, an armed gang got away with thousands of pounds after hitting a security guard.

Today the robbers seized the cash from the guards then fled in a white Vauxhall Corsa van towards Woodstock Road.

Police later removed the get- away vehicle and a silver Mercedes car from nearby Mayfield Road.

All four men's faces were covered. One is thought to be black, while the other three are thought to be white.

Police cordoned off the bank for about five hours while forensic investigators and scenes of crime officers examined the scene.

Staff at Ladbrokes betting shop, opposite the bank, have been robbed at knifepoint twice in the past two years - in November 2005 and then in September last year.

Kelly Taylor, manager of Pen to Paper, said: "It's certainly happening more frequently. We've had Ladbrokes and now the Abbey - it all seems to happen in Summertown."

Nadim Harb, manager at LB's Lebanese Cuisine, said: "We're worried, but we won't leave cash here overnight."

Rupert Griffin, 28, who lives opposite the bank, said: "I am pretty shocked. Ladbrokes was done not long ago and now this. I suppose Summertown has good escape routes."

Maher Al Kotob, 48, who lives above the bank, said: "I'm pretty shocked it has happened outside my window. I moved here because it was a safe place."

A spokesman for the Abbey would not comment on the robbery because of the continuing police investigation.

Group 4 Securicor would only confirm a member of security staff was injured in the incident.

Neither would reveal how much money was stolen nor whether they would be changing security arrangements after two identical robberies in a fortnight.

Anyone with information should call Oxford CID on 08458 505505 or Crimestoppers on 0800 555111.