Reported by China Daily, one of the safety inspectors said the new mining rules in the province would have the head officials of Lianyuan's safety stations sacked for any major incident taking place.
The inspector told the newspaper the joint resignation was because of the tough penalties and he added it was hard to be right 100% of the time.
China has been the only nation to increase its coking coal imports so far this year, partly due to local government clampdowns on the small mines sector, according to Goldman Sachs JBWere.
The biggest accident this year was the underground gas explosion in February at the Tunlan Colliery in northern Shanxi Province, which killed 78 people and injured 114.
