FOUR people were arrested and 251 cars were stopped as part of a police operation targeting travelling crooks.

Officers ran an automatic number plate recognition (ANPR) checkpoint in Bolton Road, Ewood, from Tuesday until Saturday.

Detective Inspector Jim Elston said the operation was intelligence-led in that there were specific vehicles driven by wanted criminals that they were hoping to find with the technology.

It was run in conjunction with other agencies, including Trading Standards, the Department for Work and Pensions, the DVLA and vehicle standards body VOSA.

People driving cars without tax, insurance or an MOT and motorists using mobile phones at the wheel were also targeted in the operation codenamed Incarcerate.

Over the five-day crackdown, officers stopped 251 cars, checked 158 people, made four arrests for motoring offences and clamped 13 vehicles.

Mr Elston said: "It was aimed at those people who are cold calling at the homes of elderly people with a view to ripping them off, whether that be through the price, poor workmanship or those who use it as cover for criminality to commit a distraction burglary."

PC Julie Titterington, who organised the operation, added: "I hope this operation sends out a strong message to those people who want to use our roads to carry out crime, it will not be tolerated."

ANPR reads hundreds of registration plates every hour and checks them against police databases and for tax and insurance.

If a match is found a warning is sounded so officers further down the road can pull the vehicle over.

Mr Elston said police had decided to run the operation following a number of bogus caller incidents in recent months.

He appealed for anyone with information about crimes against the elderly to call Blackburn police on 01254 51212.