A second attempt to cap a gas leak that has forced the evacuations of hundreds of people in southwest China is set for Wednesday afternoon.

"The decision on the second capping operation was made after lengthy discussions by engineers," said Du Haiyang, deputy magistrate of Xuanhan County, Sichuan Province.

The leak happened last Thursday at the Qingxi No. 1 Gas Well in Qingxi Town, northeastern Sichuan, during drilling. More than 12,000 people were evacuated immediately after the leak.

The first capping attempt was carried out early Monday, but failed because of the complicated conditions at the well.

Most of the 12,000 residents returned home after local environmental protection authorities said no toxic chemicals such as sulfurated hydrogen and sulfur dioxide, were detected in the air.

"But 723 other villagers still cannot go home because their houses are within 500 meters of the well," said Liang Tao, head of Qingxi Town.

Xuanhan County, about 500 kilometers northeast of Chengdu, capital of Sichuan, is one of China's major natural gas bases. The county is investing heavily in the development of its gas reserves.

(Xinhua News Agency December 27, 2006)