Scrap metal dealers in Bradford have been raided by police as soaring world metal prices continue to fuel an explosion in lead and copper thefts.

Officers in the Bradford South division teamed up with the Environment Agency and Bradford Council's environmental enforcement team to visit four dealers in a clamp-down on rogue traders and unlicensed carriers.

In a warning shot to scrap dealers, officers checked through records and looked for stolen goods such as copper piping and lead flashing during yesterday's raids.

Police also visited 18 people suspected of being involved in metal thefts, with the purpose of disrupting criminal activity, gathering intelligence and informing them of the consequences of future offences.

Carriers arriving at scrap yards with metal were asked to prove they had a relevant waste carrier licence.

A total of 25 vehicles were stopped and five people were caught carrying scrap metal without a licence. They were issued with £300 fines.

One vehicle was seized because it was being driven without insurance.

Inspector Gail Lawrie, of Bradford South Police, said theft of lead from roofs of churches, schools and residential homes was a continuing problem in the area.

Roadside searches were carried out in Bowling Back Lane, while several scrap yards were serached.

Dave Small, a senior enforcement officer for Bradford Council, said: "What we deal with is the unlawful carrying of waste of people in their cars or vans, who need to be registered with the Environment Agency."

Four people were caught at one site with no licences, including two on foot carrying scrap metal in carrier bags.

Mr Small said people carrying metals were also required to keep transfer notes.

He said: "We do still get people who say they had no idea at all about these rules, but we have been doing stop searches with the police since April or May last year, so most of these people today, we will have stopped anyway.

"They should all really know the rules by now."

Mike Robotham, environmental crime officer for the Environment Agency, said: "All the sites we visited have got waste managing licences you need if you are keeping or handling waste.

"There is a paper trail that we try to get people to put into place, so that we are able to trace anything if it is fly-tipped."

After visiting sites where records were previously incomprehensible, Rob Langdale, environment officer for the Environment Agency, said their record-keeping methods had been improved.

He said: "If people do steal the lead, then they should know that scrap metal dealers will be keeping records of it.

"However, the metal dealers often want to take in the metal, no matter where it has come from, because of its inherent value.

"This is why we need to try to tighten the process up, so no illegal activity can take place easily."

Yesterday also saw British Transport Police join with police forces, Government agencies and industry representatives across the UK in a national day of action to target metal theft.

About 20 police forces across the country took part in the day of action, carrying out arrests, targeting hotspots and mounting overt and covert operations.