The number of metal thefts in Telford, Shropshire, have increased during the past two weeks, police say.
Cable valued at £1,000 was taken from a yard at Rollason's in Wellington during Monday night.
A West Mercia Police spokesman said there had been an increase in such thefts in the area, not only at businesses but also at empty houses.
Copper piping had been taken from some unoccupied premises, the spokesman said.
Police will be working with scrap yards and scrap merchants in an attempt to discover how the thieves are getting rid of their stolen metal, he added.
"We're also keen to hear from anyone who wants to report suspicious vehicles such as vans or lorries that are being loaded up at unusual times such as the middle of the night," the spokesman said.