At least 87 people are now known to have died in a coal mine blast in northern China, state media report. Another 21 miners are reportedly still missing in the Xinxing pit in Hegang City, Heilongjiang province.<br/> <br/>The toll has more than doubled from 42 dead earlier. Some 528 workers were in the mine when the blast hit before dawn on Saturday local time, said Xinhua. <br/>The rising death toll makes the accident one of the worst ever to hit China's notoriously dangerous mines. <br/><br/>