Rescuers get ready at the Xinhua No. 4 coal mine in Xinhua District of Pingdingshan City, central China's Henan Province, on September 8, 2009. A total of 93 people were working in the coal mine where a gas explosion happened Tuesday morning, leaving at least 35 dead, according to local safety watchdog. [Xinhua]

The death toll from a coal mine gas explosion in central China's Henan Province Tuesday has climbed to 35 with 44 trapped underground, the local safety watchdog said.

The deadly gas blast took place around 1:00 AM Tuesday in the Xinhua No. 4 pit in Xinhua District of Pingdingshan City, said a spokesman with the Henan Provincial Bureau of Work Safety.

A total of 93 people were working in the pit when the accident happened, 14 of whom managed to escape.

City authorities have sent five teams of 70 rescuers to take part in the search and rescue operation.

The accident is arousing the attention of top leadership, including President Hu Jintao and Premier Wen Jiabao. Vice Premier Zhang Dejiang arrived in Pingdingshan with a government delegation at 1:10 PM Tuesday.

Luo Lin, director of the State Administration of Work Safety, has also led a team to Pingdingshan to oversee rescue work and investigate the accident.

Ambulances, police wagons and engineering vehicles packed the colliery's compound Tuesday morning. At 11:00 AM, at least 60 rescuers had taken turns to go down into the pit in search of victims.

"The first group of rescuers arrived at 2:00 AM and began to restore the underground ventilation system," said Zhang Jufeng, an official in charge of the city's coal mine industry bureau.

By 11:00 AM ventilation in most shafts had been restored, he said.

A preliminary investigation showed illegal mining was to blame for the accident.

The township-run colliery, which produces 150,000 tonnes of coal annually, was undergoing an overhaul and had not been allowed to resume production by the city government, said a spokesman with the Pingdingshan city committee of the Communist Party of China.

Local authorities have frozen the colliery's bank account and its owners are under police surveillance.

The Henan provincial government has ordered an immediate safety overhaul of all coal mines. Governments at city and county levels are to be held responsible for safety at all pits in their jurisdictions, said a circular issued by the province's government Tuesday.

The city government of Pingdingshan had ordered all of the city's 157 coal mines to suspend production for safety overhaul.

Coal mine disasters took 1,699 lives in Henan Province in the first eight months of this year, down 22 percent from the same period of last year, the provincial work safety bureau said.