More signs of cover-up attempts came to light over the weekend after 26 miners died in a gas explosion at a coal mine in Mianchi county of Henan province last week, an investigation team led by the provincial government said.

The deadly blast rocked the Juyuan Coal Mine at 3:35 PM on Dec 7, about two hours earlier than previously reported, the Xinhua News Agency reported on Sunday. The accident also injured 12.

The mine had been acquired by State-owned Henan Yima Coal Industry Corp from private owners before the accident. But the former owners were still managing the mine when the accident occurred.

The recently revealed time lapse in reporting the incident has raised concerns that the former owners might have used the period to hide the four miners' bodies rescuers later discovered.

The accident's death toll will weigh most in determining the levels of responsibility of the former owners, who may face prison in accordance with national laws.

In addition, the number of miners working in the pit when the blast occurred was revised on Saturday evening to 82 from 46, capping a series of upward adjustments in the tally since Dec 7.

The mine had initially reported to local authorities that 15 miners were in the mine during the blast. Work safety officials have since seen the number soar to 46 after two revisions on Dec 8.

The mine was being run despite an operational ban until the completion of its rebuilding.

Investigators said the mine's former owners were also found to have tried to hamper the rescue work and investigation.

They had managed to hospitalize injured miners in two hospitals before rescuers arrived. Both hospitals were unaware of the causes of the miners' injuries.

Most uninjured miners left the scene before rescuers' arrival, complicating the rescue and number verification efforts.

Miners' work schedules went missing, as did some of the mine's maps, while other maps were proven to be fakes.

A row of monitors had deliberately been shut down during the rescue, an anonymous rescue official told Xinhua.

The former owners also ignored warnings about the gas buildup in the shaft three hours before the explosion, State broadcaster China Central Television (CCTV) reported.

Wei Yi, a miner responsible for monitoring gas levels, had demanded production be stopped because the gas levels were too high at noon on Dec 7, Wei told CCTV. Production was paused for about half an hour before a manager ordered it resumed, Wei said.

Investigations are ongoing.

(China Daily December 13, 2010)