The official death toll has risen to 63, with 103 workers still missing, as toxic fumes slowed rescuers from entering the pit.

When the explosion occurred at the state-owned Chenjiashan mine in Tongchuan, in Shaanxi 293 miners were underground, 127 of whom escaped. It has now transpired that workers were ordered back underground a week ago even though management knew a fire was burning underground. High levels of gas were detected at the same time.

The brother of one missing employee told South China Morning Post experienced miners initially refused to return to work underground after the fire broke out but complied when management threatened them with punishment or job suspension.

Hopes of finding any survivors were dashed yesterday despite the mine’s main ventilation system being repaired, allowing rescue efforts to continue. A Communist Party Secretary gave the chances of anyone surviving as virtually nil.

Acting Shaanxi provincial governor Chen Deming ordered local government staff to bring all victims to the surface, whether they were alive or dead, the People's Daily reported.

The blast came a month after a gas explosion at the Daping mine killed 148 workers in Henan Province.