Fumes pouring from a burst gas well in China's southwest killed at least 191 people, injured hundreds more and forced 31,000 residents to flee, state media reported.
The scale of the catastrophe was huge even by the standards of accident–plagued Chinese industry, where thousands of people are killed every year in coal mine explosions and other disasters.
The blowout occurred Tuesday night at a gas field in Gaoqiao, a town in Kaixian county near the city of Chongqing, releasing a cloud of natural gas and hydrogen sulfide, the official Xinhua News Agency said.
At a makeshift hospital, 200 to 300 people were being treated for gas poisoning and chemical burns, the Web site of the state newspaper China Daily reported. A hospital employee was quoted as saying other facilities received "large numbers" of patients.
"There are farmers and miners, old and young, men and women," the employee said. "Some died after they arrived here."
Some 31,000 people living within five kilometers (three miles) of the well were evacuated Tuesday night, Xinhua said. It said special teams were searching the area for other possible victims.
Technicians were preparing to try to plug the well using cement and earth–moving equipment, Xinhua said.
They ignited the gas spewing from the wellhead on Wednesday to burn it off and stop it from spreading, Xinhua said. Photos released by the agency showed the flames shooting up into the night sky.
A team of officials led by the general secretary of China's Cabinet rushed to the scene from Beijing, Xinhua said.
President Hu Jintao and other Chinese leaders ordered local authorities to "go all out to rescue victims, prevent poisonous gas from spreading further and reduce casualty," the report said.
The disaster came amid sweeping government efforts to tighten industrial safety in China and reduce the carnage in a country with one of the world's highest rates of workplace deaths.
Despite the crackdown, the number of deaths in China's mines and factories jumped nearly 9 percent in the first nine months of this year to 11,449, according to the government.
Fatal accidents often are blamed on lack of required fire equipment and indifference to safety rules by managers.
The cause of the disaster at the Chuandongbei gas field near Chongqing wasn't clear. Xinhua said it involved a drilling mishap that broke open a gas well, but didn't give details.
The well blowout at about 10 p.m. on Tuesday spewed natural gas and hydrogen sulfide some 30 meters (100 feet) high, Xinhua said, citing Qian Zhijia, the field's deputy director.
Qian said the blowout should be brought under control by late Friday, Xinhua said.
Photos on the China Daily Web site showed women and children in the hospital in Kaixian county. Some breathed from oxygen tanks parked beside their beds. Others crowded together under olive–green quilts.
Xinhua had reported Wednesday that only eight people were killed in the accident and said the blowout already was under control. It didn't explain the discrepancy between that report and its announcement Thursday of the much higher death toll.
State television reported the disaster Thursday as the second item on its national evening newscast but gave no death toll.
The gas field, 337 kilometers (210 miles) northeast of Chongqing, is run by the Sichuan Petroleum Administration, part of state–owned China National Petroleum Corp., Xinhua said.
Employees who answered the phones at police, fire and local government offices in Chongqing and Kaixian county said they had no information about the disaster. Phone calls to the management office of the gas field weren't answered.Reuse content