More than 40 of the 293 miners were injured in the incident on November 28, 2004, some seriously.

In a related development on Wednesday, an appeals court in Xinjiang upheld a lower court's sentencing of five coal mine managers and technicians in June.

They were jailed three to six years for causing 83 deaths in a gas blast last year.

China's coal mining industry - the world's deadliest - records thousands of fatalities every year.

Relatives of the mine victims
seen in this file picture

Safety regulations are often abandoned as greed-motivated mining officials step up production to exceed normal output limits.

On Wednesday, 11 miners were killed in a gas explosion in Gansu province, which neighbours Shaanxi.

The authorities have yet to ascertain the number of those still trapped.

Four coal mine accidents occurred across China over the weekend leaving at least 85 dead.

Last year alone, 6,000 miners died in mining disasters.