Deadly blasts

March, Shijiazhuang: 108 killed by homemade bombs March, Jiangxi: 42 students and teachers killed; cause disputed July, Shaanxi: At least 41 killed, reportedly by improperly stored explosives

Police blamed the blast on explosives that were moved to Mafang after a crackdown in April on illegal explosives factories.

Rescue teams were sent to the region and police are seeking a man suspected of moving the explosives to his brother's home in the village.

Nineteen of the 22 seriously injured people are said to be out of danger.

Crackdown

China has been trying to crack down on explosives following a series of deadly blasts this year.

More than 100 people were killed in what the authorities said was a campaign by a man using homemade explosives in the northern city of Shijiazhuang in March.

The bomber and two people who sold him explosives and fuses were executed for their roles in the bombings. A fourth was sentenced to death but the execution order has been suspended for two years.

An explosion at a school in Jiangxi province in southern China killed 42 students and teachers in March.

There were conflicting reports about the cause of that blast, with officials blaming a crazed bomber, while parents said the children had been forced to manufacture fireworks.

Explosives and the chemicals used to manufacture them are easily available in China. They are used for clearing fields and construction sites and in illegal coal mining.