The last four missing miners in Saturday's coal mine blast in Shanxi Province have been confirmed dead, according to a Tuesday China Central Television (CCTV) report.

The deadly blast took place on Saturday afternoon in the Xishui Colliery near Shuozhou, a city in the key coal-producing province of Shanxi, burying 49 workers. The explosion also caused the wall of a neighboring mine to collapse, trapping another 20.

The government has begun investigating and taking care of the families of the victims.

The Xishui mine was riddled with problems such as outdated technology, haphazard management and illegal use of explosives, the Xinhua News Agency quoted Zhao Tiechui, head of the government's investigation team, as saying.

An inspector sent by the local mine safety administration to the colliery was also found to be "seriously negligent," according to Zhao, who is also director of the State Administration of Coal Mine Safety.

"It provided the mine owners with the opportunity to defy government supervision and operate without authorization," he was quoted as saying.

The Xishui Colliery was ordered to suspend production last November because of safety problems but the order was disregarded.

Technical details of the cause of the tragedy, which Zhao described as "an extremely big gas explosion," have yet to be determined, according to Xinhua.

Local police in Shuozhou detained four people for investigation on Saturday, shortly after the blast.

The Supreme People's Procuratorate has also ordered local procurators to investigate any official negligence that may have contributed to the accident, the Beijing News reported Tuesday.

"We are very concerned about the incident, and will send our men to oversee (the judicial investigation) if necessary," the newspaper quoted an official from the Supreme Procuratorate as saying.

In a strongly worded "urgent notice" released on Monday, the Shanxi provincial government ordered close scrutiny of coal mine safety throughout the province.

It also warned officials against colluding with illegal mine operators by accepting bribes, and offered a reward of up to 50,000 yuan (US$6,000) to those tipping off the government about cases of illegal mining.

"The provincial government is resorting to different approaches to try to prevent the occurrence of accidents," an official of the Shuozhou Coal Mine Safety Administration told China Daily Tuesday.

China's coal mines, among the most lethal in the world, have experienced a string of disasters since late last year. A gas explosion killed 148 in Henan Province on October 20; a blast in a coal mine in Shaanxi Province killed 166 on November 28; and the worst mining accident in half a century killed 214 people on February 14 in Liaoning Province.

Premier Wen Jiabao promised at the National People's Congress earlier this month that the central government will spend 3 billion yuan (US$360 million) upgrading safety at coal mines to "truly make coal mining safer."

(China Daily March 23, 2005)