Images obtained from Google Earth have shown what analysts believe to be a new type of Chinese submarine capable of firing nuclear warheads.

Analyst Hans M. Kristensen said in a report issued by the Federation of American Scientists that the images appear to show the submarine docked at a naval base close to the North Korean border. 

"A commercial satellite image appears to have captured China's new nuclear ballistic missile submarine," wrote Kristensen.

"The new class, known as the Jin-class or Type 094, is expected to replace the unsuccessful Xia-class (Type 092) built in the early 1980s.

"The new submarine was photographed by the commercial Quickbird satellite in late 2006 and the image is freely available on Google Earth."

The Federation of American Scientists is a non-profit organisation set up by former scientists from the Manhattan Project.

Its stated goal is to promote the non-proliferation of nuclear, chemical and biological weapons and increase public awareness of the technologies behind such threats.

The discovery highlights the increasingly diverse uses to which Google Earth and similar world mapping tools are being put - and the possible security risks.

Some sensitive facilities, such as nuclear plants and government buildings, are already being fuzzed out of Google Earth images.

US vice president Dick Cheney recently had Washington's Naval Observatory, his official residence, fuzzed out of Google Earth. Curiously both the White House and the Capitol building are still visible.