Prosecutors in central China's Hunan province are investigating five local officials in connection with a coal mine explosion that killed 29 miners last year.

The officials, including deputy head of the Hengyang Coal Bureau Zhou Caiping, have been accused of dereliction of duty in connection with the blast, according to a Tuesday statement issued by the Hengyang Municipal Procuratorate.

The five officials were supposed to have closed down the Xialiuchong coal mine in the city of Hengyang after potential hazards were discovered, the statement said.

The mine explosion occurred on Oct. 29, killing 29 miners and injuring six others.

A preliminary investigation showed that the explosion occurred when a high concentration of gas was ignited by electrical sparks.

The country's top work safety watchdog, the State Administration of Work Safety, said poor management was to blame for the accident.

A further investigation into the accident is under way.