BEIJING - China has started building a railway to a remote desert region known as "the sea of death", state media said Wednesday, a place once used as a test site for nuclear bombs.

The 360-kilometre (225-mile) railroad from the China-Mongolian border to the Lop Nur area in the northwestern region of Xinjiang will help the nation in its quest for resources, the Xinhua news agency reported.

It will improve access to potassium salt, an ingredient in some fertiliser products, and will also make it easier to reach important coal reserves in the region, according to the agency.

But apart from that, the railroad, expected to be completed in two years, will also help open up one of China's most mysterious areas.

Lop Nur was home to a little-known civilisation, Luolan, which disappeared in the third century, possibly because of an environmental disaster.

In 1980, archaeologist Peng Jiamu went missing on his fourth expedition to Lop Nur and was never found.

Lop Nur was also picked as the site for China's first nuclear bomb detonations in the 1960s.