Thieves are being warned that they are putting pedestrians and motorists at risk by stealing manhole covers.
Northumbria Police said a number of covers had been stolen across south-east Northumberland in recent weeks.
It is believed the offenders have stolen them to sell as scrap metal and any witnesses are urged to contact authorities.
Northumberland County Council said it was replacing the steel covers with heavy plastic ones to tackle thefts.
Council executive member for highways and transport, Councillor Alan Armstrong, said: "It is appalling that people are creating a hazard and a nuisance by stealing manhole covers to make a small amount of extra cash.
"It is certainly disappointing that resources are having to be used to manage the actions of these individuals."