A blast ripped through a residential building in the prefecture-level city of Yulin in Shaanxi province on Monday at around 2pm, injuring several passers-by.
The number of people injured was not yet known and it was unclear if anyone died as a result of the blast, a Fugu police officer was quoted as saying by the Huashang Daily.
The explosion was in a building near the local hospital in Xinmin, Fugu county, which was surrounded by other residential buildings, the report said.
Cars and buildings near the site sustained heavy damage, with multiple people injured. Some suffered head injuries and were rushed to the hospital, the report said.
A crater with a diameter of around 4 meters and about 2 meters deep was created by the blast.
Local police, firefighters and nearby residents are searching for other casualties.
A posting on the official Weibo account of the Yulin government at around 5:15pm said six people had been reported injured so far.
The cause of the blast is being investigated, with some local residents quoted as saying it was ignited by explosives that were illegally stored in the basement of the building.
Video footage shows heavy damage to the building, with dense smoke and debris strewn across the street.