Three workers at the gas well that blew out killing 243 people in Chongqing Municipality last month have been arrested in connection with the accident.
The natural gas well operated by the China National Petroleum Corporation, in Kaixian County, blew out on Dec. 23 last year, sending out a poisonous cloud of sulfurated hydrogen that spread through nearby villages.
A special panel was set up immediately to investigate the cause of the accident.
Investigations showed that the accident occurred after safety regulations were violated, said Wen Qiang, deputy director of Chongqing Municipal Public Security Bureau, on Sunday.
Both technical workers at the gas well, Wang Jiandong and Song Tao, are alleged to have removed the back pressure regulator inside the drill, which was strictly forbidden under the production regulations. Xiang Yiming is alleged to have injected less than the required amount of drilling fluid into drilling tools, leading to the gas build-up and the blowout.
All the three have been charged with causing a severe accident.