Police today appealed for help in stopping sneak-in thieves responsible for soaring car crime in the district.

West Yorkshire and North Yorkshire Police have joined forces in a bid to boost awareness of criminals who break in to homes, steal car keys and then drive off in the owner's car.

More than 70 sneak-in thefts were recorded in West Yorkshire alone in a three-week period up to January 11.

Now police are hoping that their high-profile 'Yor-Keys' campaign will help them track down those responsible.

Speaking at the project launch, Chief Superintendent Adam Briggs, of West Yorkshire Police, said homes across Bradford are being targeted because car keys are visible to the thieves.

But he said the level of crime could be easily countered if home-owners took simple security advice.

"This campaign is about action, not words," he said. "We are determined to catch the people who are committing these burglaries. They are causing real problems for our communities."

Chief Supt Briggs stressed home-owners should ensure their doors and windows are securely locked and keep car keys in a secure place and out of view.

In many cases keys have been snatched from worktops or windowsills, and sometimes the thieves use fishing rods or canes through open windows or letterboxes to hook them.

But Chief Supt Briggs said the joint operation between nine police divisions was ensuring that criminals would have no place to hide. "Cross-border policing will bring pressure to bear on these criminals - this is a major operation to redouble the efforts to catch them," he said.

Only 30 per cent of cars stolen from driveways in the Bradford district after sneak-in thefts are later recovered by police. The most popular targets in the Bradford North and South divisions are X- and W-registered Vauxhalls, with Fords also in demand. BMWs are the most likely to be stolen from homes in Keighley.

The vast majority of the crimes occur when thieves gain entry through unlocked doors or open windows.

Chief Supt Briggs said the problem of sneak-in thefts has soared since last autumn. "Some people think that there is just a small number of people involved, but it has now become a method of operating," he said. "It is a new trend but one that it should be quite easy for us to combat. We are giving people a simple message about what they can do, but it is one that they must listen to in order to avoid becoming victims themselves.