Mine bosses in China who don't go underground with their workers will be severely punished under a new regulation that took effect Thursday in the latest bid to improve safety in the world's deadliest mines.

Chinese Premier Wen Jiabao in July ordered mine managers to spend some time in the shafts along with their miners so that they would focus more on safety, after a series of deadly mining accidents sparked public outrage.

But China National Radio quoted State Administration of Work Safety spokesman Huang Yi as saying there have been reports of mine bosses in some areas arranging to have employees take their place in the shafts, though he didn't give specifics or say where the alleged violations happened.

"We will strictly deal with any instance of this kind of activity," Huang was quoted as saying.

The regulation calls for mines that violate the rules to pay between roughly $22,500 to $752,500 in fines, depending on whether the mine also suffers serious accidents. Bosses could be fined between $1,500 and up to 80 per cent of their income from the previous year and face a lifetime ban on mine supervision work.

Detailed regulations were issued by the work safety administration last month and came into effect Thursday.

More than 2,600 people died in mining accidents in China last year, though deaths have decreased in recent years as the government closed many illegal mines.

But deaths jumped again in the first half of this year. Coal mine deaths through June were 1,261, up from 1,175 in the same period last year, the official Xinhua News Agency reported earlier.