A senior official with the State Administration of Work Safety (SAWS)on Thursday urged the local authorities to properly handle problems from the deadly gas burst that killed at least 191people in Chongqing Municipality in southwest China.

The gas field,in Kaixian County,is some 337kilometers northeast of Chongqing Municipality.The tragedy took place at 10:00p.m.Tuesday,when a well blowout suddenly and released a high concentration of natural gas and sulfurated hydrogen.

The SAWS official said that the cause of the accident is under investigation as an investigation team sent out by the administration arrived at the blowout spot of the Chuandongbei gasfield at around 7:10p.m.Thursday.

He said localities across the country should upgrade their supervision and inspection on the safety of the production,management and storage of toxic products as the new year draws near.

Some 31,000local people living in the mountainous area around the gas field had been evacuated from their villages since Tuesdaynight amid the spread of natural gas and sulphurated hydrogen,local officials said.

Local officials feared the death toll might rise further as 20special teams dispatched to the villages by the local authorities continue searching for survivors and identifying casualties.

Sulphurated hydrogen is a kind of toxic gas that will leave people seriously poisoned or even dead with an inhalation of 760to 1,000milligrams per cubic meter.