A FIRE that devastated a substantial area of Dartmoor on Monday night is believed to have been started deliberately. An area of more than one square mile, which includes land within an Environmentally Sensitive Area and Site of Special Scientific Interest, was destroyed by the blaze. The fire near Fernworthy Reservoir started on Monday afternoon. Due to the inaccessible location and fading light, fire crews did not attempt to tackle the fire as it could have been dangerous for the crews. Firefighters, Dartmoor Rangers and the police helicopter monitored the area overnight and returned to the scene on Tuesday. There were seven areas of fire but most were burning towards watercourses and other natural breaks. The police helicopter was requested to survey the scene and make sure there were no campers or walkers at risk in the area of the fire. Keith Pascoe, arson reduction officer for Devon and Somerset Fire and Rescue Service, said: 'This fire has had serious environmental consequences for Dartmoor by damaging a substantial area of environmentally important land. 'We are working with police officers to ascertain the cause of the fire but it appears to have been started deliberately. 'Fire is very dangerous and will destroy everything in its path. If you see anyone deliberately lighting fires or behaving suspiciously call Crimestoppers on 0800 555111.' The fire follows a series of smaller fires on the moor in the last two weeks. In one recent incident near Moretonhampstead, six separate fires were started on the same evening. With the Easter weekend approaching and dry weather predicted, fire officers are also warning about the accidental ignition of moorland fires. They warn residents never to throw away cigarette ends or matches, to not light fires within the boundary of the National Parks and never leave bottles or broken glass on the moor. Cars should only be parked in designated car parking areas.