A "fishing-rod gang" - thieves who use bamboo canes and fishing lines to hook keys through people's letterboxes - is targeting homes across the region, police warned last night.

Organised teams have stolen tens-of-thousands of pounds worth of expensive cars, electrical equipment and other property from affluent homes using the sneaky technique.

Scores of properties in Sunderland have been hit by the thieves who lift the keys then use them to enter homes and steal cars from driveways.

In some cases the stolen cars have been used to transport valuables taken from homes.

Last night police said the crooks, from Wearside, were also operating in neighbouring County Durham and warned people not to leave keys where they could be reached.

In some instances keys left on hall tables or hooks 12ft away from the door have been stolen.

Some arrests have been made, but the gangs continue to be prolific, striking several times during the past few months.

The latest incident happened when a home was burgled in the Roker area of Sunderland.

Detective Inspector John Watts, of Sunderland City CID, said: "People should be aware of this and take extra care with regards to their keys.

"The premises that are targeted by the offenders tend to be more affluent homes that have high-value cars standing outside on the drive.

"There have been some instances where they have got keys and gained access to the garage then taken cars.

"They have also used keys to gain access to people's homes and valuable property has been stolen. People can help us by making sure they put their keys away securely in a kitchen drawer or in a different room well away from letterboxes or open windows."

Northumbria and Durham Police have joined forces to try and halt the thieves.

Det Insp Watts added: "These offences happen mainly in Sunderland, but they have also been into Durham.

"We have close liaison with our colleagues in Durham and other areas in relation to these offences."

Anyone with information on the thefts should call Sunderland City CID on 0191-454 7555