Firefighters are battling a moorland blaze at the same site as a similar wildfire two weeks ago.
West Yorkshire Fire and Rescue Service said 10 fire engines have been deployed at the incident near Deer Hill Reservoir.
Crews said an area extending 300m by 700m is on fire on the moor, between Marsden and Meltham.
The site lies on the northern edge of the Peak District national park. Crews and fire engines from across West Yorkshire are dealing with the fire, which follows a blaze near the reservoir on 23 March, which was caused by controlled burning spreading across the moorland.
Last year the fire service and partners launched the Be Moor Aware campaign and Bradford, Calderdale and Kirklees councils brought in public space protection orders banning barbecues on moorland and other open spaces.
West Yorkshire Fire and Rescue Service pleaded last month for an end to the burning of moorland by grouse-shooting estate managers and workers.
Many areas in England have put a stop to the practice, and muir-burning in Scotland has now been outlawed for the time being by legislation.
After a very wet winter, the past few weeks have been dry and relatively warm in northern England, leading to increased fire risk.
- The Moorland Association has asked us to point out that the fire on Monday at Deer Hill was not caused by controlled burning. It said all its local members suspended such activities from 23 March and that the fire was on the side of the hill owned by the National Trust. The association added the fire was most likely caused by arson.