(CNN) -- The death toll from an explosion at a coal mine in northern China has risen to 17, state media reported Saturday.
The head of the Peoples' Hospital in Yicheng County told the Xinhua News Agency that 104 people were injured in the blast, seven of them seriously.
It happened at Liugou coal mine in Shanxi province about 3:40 a.m. (3:40 p.m. ET Friday), Xinhua said.
Rescue crews were scouring the area for survivors. An investigation is under way.
A senior official with Yangquan Coal Industry, which owns the Liugou mine, said that a preliminary investigation has revealed that the blast was possibly caused by explosives hidden illegally in the area, according to Xinhua. The official said a suspect is in police custody, Xinhua reported.
Mine accidents are common in China. In 2009, 2,631 people were killed in such accidents. The figure, while high, is down from 2002, when 6,995 people died.
In April, the country launched a campaign to inspect safety regulations in mines and other industries that have had serious accidents.