Emergency workers are trying to seal a leaking gas well in China that has forced 11,500 villagers to evacuate their homes.
Tons of cement and slurry are being trucked in to plug the leak
The leak triggered a huge explosion in the south-west municipality of Chongqing on Saturday.
There were no initial reports of deaths or injuries and the incident has not caused any serious contamination, according to the local government.
A broken pipeline is believed to have caused the blast, the China Daily said.
A similar leak in the same area in 2003 killed 243 people.
Both accidents were in operations run by the Chuandong Drilling Company, owned by China's largest oil firm.
Tons of cement and chemical slurry were being trucked in to plug the well, Chinese news agency Xinhua said.
Checks were also being made for other possible leaks over an area extending 4km (2.5 miles) from the well.
"We are studying the possible consequences of the capping and trying to figure out how big the evacuation should be," China's official Xinhua news agency quoted Chongqing's vice mayor Zhou Mubing as saying.
Authorities evacuated 10,000 people from the area on Saturday and another 1,500 on Sunday evening, Xinhua said.
Officials have warned local residents against drinking water from a nearby river in Gaoqiao town, Kaixian county, where the accident took place.
A gas leak in the same area in December 2003 spread toxic hydrogen sulphide across mountain villages, killing 243 people in one of China's deadliest industrial accidents.
More than 41,000 villagers were forced from their homes and thousands of survivors suffered lung damage and burns on their eyes and skin.
Six gas company employees were sentenced to prison in 2004 for negligence.
Industrial accidents are increasing in China. Last year a chemical spill in the country's north-east left the residents of Harbin without water supplies for several days.