At least nine died and six were injured in an explosion in northern China's Shanxi province on Saturday evening, state news agency Xinhua reported.
Xinhua said the blast occurred in a residential building and it was believed to have been caused by illegally stored explosives. The authorities said an investigation was going on.
The state broadcaster CCTV said a number of buildings collapsed and search and rescue work continued on Sunday afternoon.
This is the latest in a series of industrial accidents in China. Explosions at fireworks factories are also quite common. Reports show that previous blasts were blamed on improperly stored chemicals or industrial explosives.
In October, 14 people were killed in neighbouring Shaanxi province when a blast caused by illegally stored explosives destroyed a block of prefabricated houses.
In 2015, 165 people were killed in a series of powerful blasts at a chemicals warehouse in the northern port city of Tianjin. Cases of people deliberately setting off blasts have also been reported in China just to settle grievances such as land disputes.
The authorities had launched a province-wide investigation into explosive production and storage. Both Shanxi and Shaanxi have large coal mining industries, where explosives are regularly used.