Sixteen miners had been killed in the accident, officials said.

Most of the casualties were suffocated after inhaling toxic smoke. Some of them died in hospital, said medical workers at the Luoshan gold mine in Zhaoyuan City, Shandong Province.

The majority of the more than 39 miners being treated in local hospitals did not have life-threatening conditions, doctors said.

Local officials said the sudden fire broke out at the mine at about 5 p.m on August 6 after an electric cable caught fire. A total of 329 miners were working underground at the time. The underground blaze was put out hours later and power supply gradually restored.

The cause of the accident is being investigated, official said, and the owner of the mine, run by Lingnan Mining Co. Ltd., had been taken into police custody, though the mine was fully licensed.

Also on August 7, a gas outburst trapped six miners underground at a coal mine in Shifang City, southwest China's Sichuan Province, local authorities said.

The rescue is underway while there is no report of casualties yet.

Last year, 2,631 people died in 1,616 coal mine accidents, according to official statistics.