Thugs who conned their way into elderly people's homes in Oxfordshire may be raiding houses across the UK.

Det Sgt Chris Biddle, of Abingdon CID, said the raiders had struck twice in Oxfordshire and eight times in the Thames Valley area.

Det Sgt Biddle said: "We are being extra alert and at certain times of the day you might see extra police officers patrolling. We are liaising with the Metropolitan Police. We think these raiders might be travelling all over the place, and have called for a nationwide alert."

The latest burglary happened when two men knocked at the door of a couple in their 80s in Parkside, Marcham, at 2.30pm on Monday claiming to be working on the water supply.

The householder reluctantly allowed them in before noticing a third man had slipped into the house and told him to stay put.

Police spokesman Tim Wiseman said: "The first two men then searched the house before all three left, stealing a sum of cash."

The three men were white, with Irish accents. Det Sgt Biddle said the raid could be linked to a burglary in Cutteslowe, on Friday.

As reported, three white men broke into a 74-year-old woman's home, threatened to kill her dog and stole £200. The raiders drove off in a black BMW.

In another raid, police said three men stole cash from a 66-year-old woman in Shrivenham on Friday.

Call police on 08458 505505 or Crimestoppers on 0800 555111.