A deepening investigation into Tuesday's deadly coal mine blast in central China revealed that 82 miners, instead of 46 as previously reported, were working underground when the gas explosion occurred, officials said Saturday.

However, the number of casualties was not changed, the investigation team of the blast said in a terse report.

Twenty-six miners were killed, 12 injured after gas explosion hit Juyuan Coal Mine in central China's Henan Province on Dec. 7. Forty-four miners managed to escape unscathed.

The time of the blast was also scaled back two hours from 5:40 p.m. to 3:35 p.m., according to the report.

Investigators said they will still probe the case to determine the cause behind the errors in numbers.

Illegal operation and lax supervision were blamed for the blast. The mine had been known as the Suzhuang Coal Mine and was re-launched as Juyuan as it was merged into the large state-owned conglomerate Yi Ma Coal Industry Group. Juyuan's owner and managers are in police custody.