Motorists in Hertfordshire are being urged to remain vigilant following a rise in the number of thefts of catalytic converters in the region.
The thefts are occurring at all times of the day and night, police said.
Thieves are targeting industrial estates as well as residential areas, with vans predominantly hit.
Hertfordshire Constabulary has set up a new dedicated task force to try and tackle the problem.
The Operation Devon team will target those who steal metal and work with scrap metal dealers to improve processes for accepting scrap metal.
Detective Chief Inspector Liz Hanlon said: "We're also experiencing a rise in theft of number plates generally and theft of tools from vans so the message extends to everyone to be vigilant, secure your vehicles and report suspicious activity straight away."
Copyright Press Association 2012