Villagers making detonators in home factories sparked explosions that killed six, injured six others and destroyed two houses, state media reported Wednesday.
The deaths occurred in three different incidents on Sunday and Monday in the central province of Henan, where rural residents were assembling the devices by hand, the Xinhua News Agency said.
Police and industrial safety bureaus were investigating, it said.
Such detonators are usually bought by small coal mines and quarries that dot the countryside throughout China. Many are unlicensed and pay scant attention to safety, but are protected by local governments for which they generate funding and jobs.
China has tried for years to crack down on the production and storage of explosives and fireworks in private homes that are blamed for scores of deaths annually.