A blast at a colliery in China has killed 21 miners and left four more missing, the BBC reported quoting state media as having said Wednesday. The accident happened at a pit in Guizhou province on Tuesday night. Fifty-eight workers escaped what it called an "outburst of coal and gas". Rescue teams were looking for the remaining four. A search was also ongoing for 18 miners missing after a mud flow at a site in Heilongjiang on Monday.