China has successfully excavated combustible ice, a kind of natural gas hydrate, in permanent tundra in the south margin of the country's northwestern Qilian Mountains, the Ministry of Land and Resources said Friday.

Samples of combustible ice were collected in the area in November 2008, making China the first country to collect the gas hydrate in tundra in the medium and low latitudes, according to the ministry.

It also shows that China has become the third country successfully excavating gas hydrate from a land-based area in the world after Canada and the United States, the ministry said.

Preliminary research shows that the prospective volume of natural gas hydrate in the country's frozen earth regions is estimated to reach 35 billion tonnes of oil equivalent.

China successfully excavated combustible ice from below the floor of the South China Sea in May 2007.