Rescuers said yesterday there was little hope that 11 missing miners survived a gas leak in a central Chinese coal mine that killed 26 of their colleages, after Chile offered help in the operation.

Du Bo, the deputy director of the rescue operation, said it would take days to find the miners, who were trapped when a “sudden coal and gas outburst” hit on Saturday in the central province of Henan, state media reported.

“There is not much of a chance that the 11 trapped miners could have survived and it will take three to four days to find them,” Mr Du was quoted as saying by the official China News Service.

The missing miners were likely buried amid the more than 2,500 tonnes of coal dust that smothered the pit after the gas leak, suffocating most of the victims, Mr Du said, according to the official Xinhua news agency.

A total of 276 miners were at work below ground when the disaster happened in the city of Yuzhou and 239 managed to make it to the surface, the national work safety agency said, confirming the death and missing toll.

Chilean President Sebastian Pinera offered to help China, saying his country had learned from the San Jose mine disaster in northern Chile, where 33 miners were trapped for two months before being pulled out alive last week.

“If we can be of any help, they know that they can count on us,” Mr Pinera said during a visit to London.

China’s latest tragedy highlights the appalling safety conditions in its mines, in which over 2,600 miners perished last year, according to official figures. Rescuers said the missing miners were 50 to 80 metres below the pit entrance but the heavy dust slowed their progress through the narrow tunnels.

The Henan mine is owned by a consortium that includes China Power Investment Corp. – a major state-owned power producer, Xinhua said.