Children are being warned not to play in derelict buildings following a spate of fires suspected as arson.
Police issued the safety warning after disused farm buildings and barns were set alight in remote locations around Harrogate.
Fires happened at locations off the A61 between Harrogate and Killinghall. Shop skips outside B&Q on Skipton Road had also been torched, North Yorkshire Police said.
Police Constable Liz Rutter said: "Some of the sites are derelict and extremely dangerous. They may be structurally unsafe, they may contain sharp objects or agricultural chemicals and they’re remote, so they’re a long way from help if anyone did get hurt.
"We have concerns for the safety of children visiting these premises unsupervised. Add deliberate firestarting into the mix, as we believe has happened at a number of these locations recently, and it’s a recipe for disaster."
A police spokesperson added: "Ten young people have been interviewed in relation to their suspected involvement with the incidents and enquiries are ongoing.."
Anyone with information is asked to call North Yorkshire Police on 101 or Crimestoppers, anonymously, on 0800 555111.