A mysterious sinkhole spewing fire and incredible heat has appeared in a Chinese hillside . Geologists and media have flocked to the desolate mountain on the outskirts of Urumqi , in Xinjiang Uyghur Autonomous Region in north-western China , since it appeared a few weeks ago . Scroll down for video . The hole appeared recently after locals noticed the ground nearby getting warmer . The heat blasting from the 'ring of fire ' has been measured at 792C ( 1457F ) from two metres away , reports People 's Daily Online , and is so intense that experts ca n't get close enough to determine how deep the hole is . Video footage of the 3ft-wide hole shows locals igniting branches and grass by pushing it to the rim . Some Chinese internet users have branded it a 'gateway to hell ' after viewing the pictures . Experts ca n't get close enough to determine how deep the mysterious hole is . The temperature has been measured at 792C - but that was from two metres away . Locals told Chinese media that they had noticed the ground in the area had been warm underfoot for some time . The hill is not in a volcanic area , and experts from Xinjiang Meitian Geological Bureau think the hole is caused by the layer of spontaneously combusted coal underneath the ground , which leads the surface layer to collapse . ‘ The phenomenon has existed in the area for a few decades , ’ Huang Wei , an engineer from the bureau told China Central TV Station . He added that smoke often comes from under the ground on this hill in the spring and autumn . Branches and grass that are held near the hole immediately catch fire from the intense heat . Experts think a coal seam may have spontaneously combusted below ground . Chen Long , a supervisor from Xinjiang Meitian Fire Engineering Bureau , said there used to be more than a dozen of small coal mines in the area in the 1970s . ‘ Primitive mining and extinguishing techniques caused coal to burn deep under the ground , ’ said Mr Chen in the same interview . ‘ Operators didn ’ t seal the mines properly after business discontinued and this leads the underground fire to burn towards the surface of the earth. ’ The local authorities have started drawing plans to put out the underground fire .
Locals had noticed the ground in the area was warmer than usual . Experts ca n't get close enough to determine how deep the hole is . Temperature measured at 792C from two metres away . Thought to be caused by a coal seam spontaneously combusting .