Eighteen tons of explosive material discovered after a deadly blast in a fireworks factory in the city of Xinji, North China's Hebei Province, were detonated on Friday morning.

The materials were found while police were clearing debris from the factory site where 29 people were killed and 91 injured on Monday.

Before the leftover powder was detonated, nearby villagers and workers in local factories were evacuated to safe areas.

Xinhua quoted Xue Heping, who was in charge of Friday's detonation, as saying no one was killed or injured and no houses were damaged by the explosion.

Sudden heavy rain in the area also reduced the risks involved, Xue noted.

Four people allegedly responsible for the factory blast have also been arrested, according to another Xinhua report.

Of the four, two are vice-directors of the fireworks factory and the other two are the factory's safety production supervisors. The boss of the factory was killed by the blast.

The Legal Daily reported that just four days before the accident occurred, the local fireworks monitoring station served a notice on the factory, asking it to stop production. However, the factory director with the surname Yang and vice-director Liu only changed the time of production.

On July 18, police went to the factory to carry out a safety inspection, but products and raw materials in the factory had been transferred elsewhere and were returned after the inspection.

Doctors in Shijiazhuang, capital of Hebei, are treating those injured in the blast.

Burns experts Sun Yonghua and Zhou Yeping, both from Jishuitan Hospital in Beijing, and liver and gall bladder expert Li Guangming, from Beijing People's Hospital, are among those working on the wounded, according to Beijing Youth Daily.

(China Daily August 2, 2003)