Forty-five miners trapped underground after a rock blast in a Chinese coal mine were brought to the surface Saturday in a rare successful rescue, CCTV state television reported.

Eight people had been confirmed killed by Thursday's accident at the Qianqiu colliery in the central province of Henan, it said. Another 21 had earlier been brought out.

Emergency personnel had to dig a tunnel at a depth of several hundred metres to reach the trapped men, and CCTV -- which covered the rescue live -- showed miners emerging from the colliery's main lift more than 36 hours after the blast.

Some were still wearing their miner's lamps, and all of them looked tired and had blackened faces.

Most were able to walk, sometimes with the support of rescuers, as crowds looking on in the town of Sanmenxia live cheered.

The last miner to be rescued was carried out on a stretcher and immediately taken away by ambulance.

While mining accidents are common in China, it is unusual for so many people to be successfully brought to the surface alive. The operation is the most successful such effort in the country since April 2010, when 115 miners were rescued after eight days trapped underground at a mine in northern China.

In October last year 33 workers trapped underground for 69 days in a mine under Chile's Atacama Desert were pulled out in a dramatic 22-hour rescue.

In the latest accident the miners were trapped by a rock burst -- a violent explosion caused by huge pressure -- moments after a minor 2.9 magnitude earthquake, according to the official Xinhua news agency.

It was not immediately clear whether the earthquake directly caused the accident.

A total of 74 people were in the shaft at the time, CCTV said.

The colliery is part of the Henan Yima Coal Mine Group, a giant state-owned mining company.

The incident was the latest to hit the hazardous mining industry in China, and came days after a gas explosion at a state-owned coal mine in neighbouring Hunan province left 29 miners dead.

Earlier in October, blasts at mines in the southwestern city of Chongqing and the northern province of Shaanxi killed 13 and 11 miners respectively.

In 2010, 2,433 people died in coal mining accidents in China, according to official statistics -- a rate of more than six workers per day. Campaigners suggest the true figure is likely to be far higher.

China's rapid economic growth has caused demand for energy, including coal, to surge. Critics say some mining bosses have put the safety of workers at risk in their pursuit of profit.

China is the world's leading consumer of coal, relying on it for 70 percent of its growing energy needs.

Over the past eight years it has on average built one coal-fired power station a week. And with the arrival of winter, mines are operating at full capacity.

"In this season when coal consumption and prices are high and profits lucrative, the heads of (mining) companies should pay extra attention to safety," Luo Lin, head of the State Administration of Work Safety, said Saturday.