BAIYIN, Gansu -- Nineteen injured miners, including six seriously injured, after a coal mine gas blast in northwest China's Gansu Province are still not out of danger, local doctors said on Wednesday.

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The explosion at 12:16 p.m. Tuesday killed 29 miners at the Weijiadi Coal Mine of Jingyuan Coal Industry Corporation in Baiyin City, about 100 kilometers northwest of Lanzhou, the provincial capital.

The miners suffered burns and fractures and would not be considered out of danger for at least three days, said doctors at the corporation's hospital.

More than 60 doctors, including three from the provincial people's hospital, are treating the miners.

Wang Shuhe, vice director of the State Administration of Coal Mine Safety, arrived at the mine to oversee the investigation early on Wednesday. The administration and the provincial government have begun a joint investigation into the cause of the blast.

Initial inquiries show some miners were checking the ventilation system when the blast occurred.

In a separate incident, 16 coal miners were trapped underground after a landslide in the same province on Wednesday morning.

Coal mine accidents in China killed 2,900 people in the first eight months of this year and 5,986 last year, according to the State Administration of Work Safety.