Crews tackle four mile long moorland fire at Baitings Moor
Fire crews have been tackling a blaze on a four mile (6.4 km) stretch of Pennine moorland.
The West Yorkshire Fire Service was alerted to the fire at Baitings Moor, Soyland, near Ripponden at 13:46 GMT on Friday.
A spokesperson for the service said 10 appliances were at scene and 36 beaters were being used to tackle the fire.
Yorkshire Water, which owns the land, has warned many areas of moorland are unusually dry.
Matt Thompson, from Yorkshire Water, said: "While our reservoirs are at normal levels for this time of year, many of the catchment areas around them are very dry.
"The heather and bracken haven't really begun to put out new shoots yet so the dead vegetation left from last year is vulnerable to fire at this time of year, particularly if it's dry."
Mr Thompson urged visitors to take care not to start fires on moorland during the dry spell.