KUNMING -?Nine people were detained last Friday following a coal mine gas explosion that killed 14 miners on April 21 in Southwest China's Yunnan province, a local procuratorate announced Tuesday.

Those arrested included the investor of the coal mine Chen Hongrui, legal representative Yan Bangjin, head of the mine Wang Wenjian and six other deputy coal mine leaders, said the Fuyuan County People's Procuratorate in Qujing City, a major coal production base in eastern Yunnan.

It said the nine were arrested for breaking work safety rules and avoiding work safety supervision, leading to a serious accident with casualties.

An investigation also showed that two technicians who were on duty failed to detect the excessive gas, eventually resulting in the tragedy. They are being pursued by the police.

The accident happened at around 12:30 a.m. on April 21 in a pit of the privately run Hongtutian Coal Mine when 56 miners were underground in Fuyuan county, with 42 escaping without injuries.

Ten local officials have been removed or suspended from their posts pending further investigation as a result of the accident.