The blast occurred in a residential building and was believed to have been caused by illegally stored explosives, Xinhua said. An investigation was underway.
A number of buildings collapsed and search and rescue work continued on Sunday afternoon, said state broadcaster CCTV.
China has a poor record of industrial explosive accidents in residential areas.
In October, 14 people were killed in neighbouring Shaanxi province when a blast caused by illegally stored explosives destroyed a block of prefabricated houses.
Both Shanxi and Shaanxi have large coal mining industries, where explosives are regularly used.
(Reporting by Cate Cadell, Editing by Randy Fabi)
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)