(Yicai) May 25 -- Eighty-two people have been killed and two others are missing after a gas explosion at a coal mine in China, according to local authorities.

The blast happened at 7.35 p.m. on May 22 when 247 workers were underground at the Liushenyu Coal Mine in northern Shanxi province, the Changzhi city government announced at a press conference the following day. Eighty-two people lost their lives, two are unaccounted for, 128 have been hospitalized, and 35 escaped unarmed.

Some 335 rescue personnel and 420 medical staff have been deployed to the site, along with mobile hyperbaric oxygen chambers and 86 ambulances, the local government said. The authorities are closely monitoring underground methane and carbon monoxide levels to prevent secondary accidents.

Rescue efforts are complicated due to underground conditions, China Central Television reported yesterday. Two tunnel floors collapsed during search operations, revealing two previously uncharted hidden passages that required additional investigation.

The Liushenyu Coal Mine, which is run by Tongzhou Group, has a designed annual capacity of 1.2 million tons and is classified as a high-methane mine. Preliminary findings indicate that Tongzhou had committed serious violations, the local government said, adding that the cause of the accident is still under investigation.

The authorities have ordered all four of the company’s coal mines to halt operations for corrective measures, and placed the company’s de facto controller, key executives, and other responsible personnel under legal control measures.

At the emergency rescue command center, several surveillance monitors remained frozen on footage from the night of the accident, and the equipment had gone offline, according to CCTV.

Editor: Futura Costaglione