Evacuees began returning home Sunday morning after their villages were confirmed safe,one day after the capping of the gas well which blew out on Dec.23in southwest China.

"Air and water in most villages are safe now and evacuees can begin returning,"said Zhang Shaozhi,director of the local environment protection department.

The gas blowout in Kaixian county of Chongqing killed at least 198people and injured 9,000others.A total of 64,000residents had moved from the accident area.The blowout gas well was successfully sealed off at 11:00am Saturday.

Tests conducted by environment protection and health experts indicate that most parts of the affected area are safe,but some villages still showed high concentrations of poisonous gas.

Drinking water,grain and vegetables were basically safe,but water near the blown out well still contained poisonous sulfuratedhydrogen which easily dissolved in water,said Zhang Chengyong,director of the Disease Prevention Center in Kaixian.

Environmental workers are conducting another test of the sulfurated hydrogen in the water around the No.16gas well.If the water is not safe,the return of evacuees who live near the well will be postponed,said Zhang.

The environment near the accident site is still being monitored.

Experts said there will be no new blowouts of the sealed No.16gas well.

"So far,no unusual activity has been detected since the gas well was sealed off on Saturday,"said Zeng Shitian,an expert working on the capping operation.The gas well is safe now and would not affect evacuees'return,said an expert from Sichuan Petroleum Administration Bureau.

Gao Deli,a professor with the University of Petroleum in Beijing,said it is impossible for the natural gas,contained 4,000meters underground,to leak out elsewhere.

According to experts,the No.16natural gas well,operated by the China National Petroleum Corporation,is still useable and canbe further developed.

However,the accident site,including the well,will be strictly checked before further operation,Gao said.

China's Ministry of Civil Affairs has sent over 10,000quilts to the affected area,a spokesman for the county government said Sunday.The county has also received over 300tons of food,medicine and other donations from neighboring areas,the spokesmansaid.

The gas blowout,the worst of its kind in China,was also the worst work safety accident in the country in 2003,according to the State Administration of Work Safety.