Tougher safety regulations for worksites will come into force tomorrow in a bid to cut the number of major accidents caused by sub-standard machinery and equipment.

The Regulation on Safety Supervision for Special Equipment has been revised to tighten measures and also maps out the procedures for government probes into incidents, which are now divided into four categories. The regulation was first implemented in 2003.

It states the "most serious accidents" - 30 deaths, at least 100 injuries or a financial loss of more than 100 million yuan ($14 million) - will be investigated directly by the State Council. Local governments will assist and help victims get compensation from insurance firms.

Industrial facilities that fail to prevent the release of toxic gases, resulting in the evacuation of more than 150,000 people, will also be classed in the "most serious accidents" category.

Special equipment is defined as those that pose a potential direct threat to safety, such as boilers, pressure vessels, chain blocks and large-scale entertainment rides including roller-coasters.

The rules also urge firms to insure facilities so victims can be compensated quickly in the event of a tragedy.

There were 307 worksite accidents last year, a 20 percent increase on 2007, said the General Administration of Quality Supervision, Inspection and Quarantine (AQSIQ), the nation's top quality watchdog.

The accidents claimed 317 lives and injured 296. Three of the incidents, which killed at least 10 people each, have been termed "major".

The number of such accidents in China is six times higher than in other major countries, admitted Chen Gang, director of the special equipment bureau at the AQSIQ.

"Major worksite accidents still pose a threat to a lot of lives, especially those working in the construction sector, where most major incidents occur," he told reporters in Beijing. "Small manufacturers are more prone to produce substandard equipment and some underground workshops in undeveloped areas are sometimes untraceable."

The worst accident involving large facilities last year was at a construction site in Changsha, Hunan province, on December 27. Seventeen workers were killed and one seriously injured when a lift dropped to the ground.

Supervising officials said they were alarmed when they heard of a freak accident in Taiwan province this month, when a crane collapsed and fell onto a tourist bus, killing three mainlanders.

The AQSIQ, however, is optimistic the revised regulation will help reduce the number of accidents and clarify compensation responsibilities.

"Investigations will reveal whether it is the designers, manufacturers or users who are responsible for the damage," said Song Jihong, deputy director of its special equipment bureau.