At least 203 miners have been killed after a gas blast at a coal mine in China, state news agency Xinhua said.
Investigations are underway into the cause of the accident
The accident, in China's north-eastern city of Fuxin, is the most deadly reported mining disaster since the communist party took power in 1949.
It left a further 22 people injured, one seriously, and 13 trapped.
A BBC correspondent in Beijing says the disaster again underlines the government's inability to ensure safety in its overstretched mining industry.
Rescue operations began immediately after Monday's blast 242m (794 feet) underground at the Sunjiawan mine in Fuxin, Liaoning province.
"We have never seen such a big accident before," a local mining official told the Reuters news agency.
President Hu Jintao and Prime Minister Wen Jiabao called for local officials to take "all possible measures" to rescue trapped workers, state television reported.
CHINA'S MINING DISASTERS
World's most deadly mining industry - 6000 killed in 2004
Demand for energy jeopardises safety
Government did not disclose details of accidents until recently
World's most deadly mining accident took place in China in 1942 - 1,549 people died in Japanese-occupied Manchuria
An inquiry is under way into the cause of the accident.
Underground explosions are often blamed on a lack of ventilation equipment to remove gas that seeps from the coal bed. Fuxin, as one of China's oldest coal mining regions, could be a particularly risky place to work as miners must tunnel far underground to reach coal seams.
Workers reported feeling something shake the mine 10 minutes before the blast, Xinhua said, quoting Zhang Yunfu, vice general manager of Fuxin Coal.
Moments later, gas detectors lost their signals and one of the mine's main pits filled with smoke, it said.
A Fuxin resident said many of her neighbours worked for the mine.
"We are of course very shocked and feel very sad about it because people are still enjoying the Lunar New Year," she told state media.
Another local, doctor Zhao Yunfu, said: "I really can't believe it, I thought the mine had stopped production [for the holidays]."
According to official figures, more than 5,000 people died in explosions, floods and fires in China's mines in 2004.
The toll was 8% lower than in 2003, the government said. Nevertheless, Beijing admits China's fatality rate per ton of coal mined is still 100 times that of the US.
China last year produced 35% of the world's coal but reported 80% of global deaths in colliery accidents. The industry cost the lives of 15 miners a day in the first nine months of 2004, according to the official figures.
Monday's blast was the deadliest since 166 miners were killed in a gas explosion at the Chenjiashan mine in Shaanxi province in November.
Following that accident, the State Council ordered an inquiry and newspaper editorials called for a more humane and balanced view of economic progress.
China has two kinds of mines: big, state-run operations, which are generally thought to be safer, and smaller private mines where the majority of deaths occur.
Correspondents say energy shortages mean the price of coal has gone up, leading some unscrupulous mine operators to cut corners to increase production.
Others have been accused of re-opening mines which had been shut down because of poor safety standards.