"This morning they made the announcement to a handful of reporters at the command center," Yan Mangxue, the party secretary for a nearby village where some of the dead miners are from, told Agence France-Presse.

"They made the conclusion because there's no chance anyone would survive."

State-run China National Radio also reported the announcement, making the disaster the country's worst mining accident in recent history.

A total of 293 workers were underground at the government-owned Chenjiashan coal mine at Tongchuan city in northern Shaanxi province when the tragedy happened Sunday. Some 127 miners escaped.

After hearing Wednesday's news up to 800 relatives, colleagues and local residents protested outside the township government office where the command center had been set up and demanded officials meet them.

"When no one came out, 40 to 50 of the protestors stormed the four-storey building, smashing the windows and breaking office furniture and equipment," said Yan, who along with other officials had been asked to inform and console relatives.

"They're very angry... They want to beat anyone in sight," Yan said by mobile phone. He and about 25 officials were trapped inside the building.

"The situation is very dangerous," Yan added, saying one local official was punched several times and his face was covered in blood.

Thirty soldiers from the army's People's Armed Police unit arrived and surrounded the protestors outside, said Yan. All police officers from the area were dispatched to the riot, as protestors yelled, "The government doesn't care about people's lives!"

By Wednesday evening the protestors had returned to the mine and forced their way into a courtyard. They demanded to be allowed through a gate to the pithead where the miners' bodies remain, Yan said.

Around 400 soldiers had arrived and were reinforced by some 300 local police but could not disperse the crowd, Yan said.

"There are too many people. Authorities are considering using high pressure water cannon to push them back," said Yan.

Families had been hoping for days to get some answers but no high-ranking government official has yet come out to meet them. "They're too scared to come out," Yan admitted.

Local officials and families blame the explosion on negligence and greed by managers of the state-owned mine. They say managers ignored dangerous gas levels detected several days before and insisted miners kept working.

"We are most upset by the fact that this could have been prevented. They have direct responsibility," said Wang Hongwei, a miner whose brother-in-law is among the victims.

Wang said his brother-in-law has left two young children and elderly parents who were so upset they had to be hospitalized.

Xinhua news agency said 101 bodies still remain in the mine while 65 had been retrieved. "It could take about 10 days before all the bodies are brought up," Yan said.

Recovery work was being hampered by continuing dangerously high gas density and the risk of another explosion. Areas of the shaft were still on fire, Xinhua said.

China, the world's biggest producer and consumer of coal, has significantly increased production in the past year to meet the demands of rapid industrialization. Critics and miners say lives are being sacrificed.

More than 7,000 workers are killed each year in China's coal mines, considered the world's most dangerous. Labour rights groups say the real figure could be around 20,000 as many accidents are unreported.

The blast Sunday followed another gas explosion last month which killed 148 miners in central Henan province. Four employees of the mine have been detained, accused of failing to evacuate miners in time despite detecting unsafe concentrations of gas half an hour before the blast.

Sunday's blast also exceeded in casualties the last reported major mining accident in China -- a gas explosion in 2000 that killed 162 miners in southern Guizhou province.