Police have arrested the suspected owner of an illegal detonator workshop in north China and they are seeking another after two explosions left five people dead and nine injured.

"The detained suspect is surnamed Zhao, who ran the workshop with another suspect surnamed Zuo in rented houses," said a police officer with Ulanqab City, Inner Mongolia.

Two detonator explosions within half an hour occurred around midday on Thursday in a residential area of Jining district in Ulanqab.

The blasts flattened nine rooms in four buildings and damaged dozens more. The number of casualties may rise as rescuers are still clearing the debris, according to the police officer.

The dead included a 45-year-old woman teacher, her mother and sister, whose house neighbored the workshop, while the other two were probably workers in the workshop, police said.

Most of the injured were residents who lived nearby or came to watch after the first explosion and were caught in the second blast, according to the police.

At least three injured people are described as critical, doctors and family members said Friday.

Police found nearly 62 barrels, weighing almost two tons, of materials for making detonators at the house of Zhao's mother-in-law, near the site of the explosions.

Zhao told his mother-in-law that they were barrels containing oil paint, according to police.

Neighbors of the workshop said Zhao moved into the rented house less than a month ago, but they did not know he was illegally making detonators.

Almost 300 kilograms of gunpowder was found on Friday at another site frequented by Zhao, 30 kilometers from Jining District, said police. Police said the workshop was probably exploiting business opportunities in the widespread illegal mining industry in Inner Mongolia.

A privately made detonator, which only costs 0.5 to one yuan (US$ 0.06 to 0.13), can sell for 10 to 15 yuan (US$ 1.2 to 1.9) on the black market. The illegal production of detonators often leads to fatal accidents in China.

Early this month, five people died and another was injured in an explosion in an illegal workshop for electronic detonators in north China's Hebei Province.

(Xinhua News Agency December 30, 2006)