The death toll from a blast in north China triggered by improperly stored explosives in a house rose to 49 after the homeowners' bodies were recovered, Xinhua News Agency said.

Wang Wenyi, 35, and his wife were found Sunday in the rubble in Dongzhai village in Shanxi province, Xinhua said. The report late Sunday did not give details on why the explosives were in the house.

Shanxi is the country's top coal producer and accidents caused by the improper manufacture, use and storage of explosives for mining are common.

Xinhua said Wang was once punished for running an illegal coal mine. He had bought the home from his brother-in-law, Sun Lifeng, who was being held by authorities for questioning, Xinhua said.

Investigators say at least 200 kilograms (440 pounds) of dynamite were detonated in Friday's disaster, which started when a fire broke out in the house, according to Xinhua.

The building exploded as villagers were trying to extinguish the flames, it said.

Some 30 people who were injured were in stable condition, Xinhua said.

The dynamite was hidden in one room of the house and other rooms were occupied by renters, it said, citing local authorities.