A helicopter was drafted in today to drop water on a moorland fire which more than 100 firefighters have been battling since Wednesday.

North Yorkshire Fire Service said the blaze on Fylingdales Moor, in the North Yorkshire Moors National Park, was still going strong and 15 fire engines fought the flames overnight.

People have been evacuated from around half a dozen farms in the area, a spokeswoman for the service said. No injuries have been reported.

The spokeswoman said: "At 4am we requested a helicopter to put water on the fire. It will probably get its water from a nearby reservoir or lake."'

Heavy moving equipment has been moved in to create fire-breaks in an attempt to stop the fire from spreading further. The fire was reported to the fire service on Wednesday afternoon and covers more than four square miles. Early indications are that the fire was started in a waste bin.

Divisional Officer Ian Bitcon said: "This fire may be a result of somebody carelessly discarding a cigarette or a barbecue into the bin. I urge visitors to the North Yorkshire Moors and the Yorkshire Dales to take particular care when visiting these beautiful areas."

The fire service said the blaze was a good distance away from RAF Fylingdales - the top secret early warning radar station on the North Yorkshire Moors.