Nearly two centuries after railways were invented, this symbol of modern civilization has finally made its way into Tibet, the "roof of the world."

At about 11:30 am Tuesday, two 25-metre-long rails were laid at the Amdo Station, some 440 kilometres from Lhasa, at the foot of the Tanggula mountain range in Amdo County of Tibet.

Sprawling on the range known as "insurmountable even by eagles" by locals and regarded as the cradle of the Yangtze and Lancang rivers, the Qinghai-Tibet Railway will boast a maximum altitude of 5,070 meters. That will make it railway at the highest elevation in the world.

With an investment of 26.21 billion yuan (US$3.16 billion), China began the construction project in 2001 to connect Golmud City of Qinghai Province and Lhasa, capital of Tibet. It is hoped it can serve as a bridge for the autonomous region -- isolated by its high altitude and severe natural environment -- with the rest of the country.

The Chinese government also hopes the project will put Tibet's social and economic development on track and help spurt less-developed western regions of the nation.

The 1,142-kilometre link is scheduled to be completed in 2007.

Days before the track-laying ceremony, residents in Amdo County had hung national flags on their tents and houses, a practice for major festivals.

More than 200 Tibetan herds arrived from more than 100 kilometres away, some of them riding horses, to witness the ceremonial occasion.

When the first rails were laid, people let out hurrahs in Tibetan, Han and other ethnic languages.

Vice-Premier Huang Ju sent a congratulatory message on behalf of the Chinese central authorities, and encouraged construction workers to build a world-class railway on "the roof of the world."

"The railway will benefit the people in Tibet and Qinghai," said Dazhag Danzim Gele, the Fourth Living Buddha with Dazhag Temple in Tibet. "It will also make the pilgrimage to Lhasa more convenient."

Lhasa is a holy place for Tibetan Buddhists.

"This is the happiest event for me," said 63-year-old Surkang, a Tibetan herdsman who tied a hada to the first rail. The hada is a white silk scarf regarded as a symbol of respect and a blessing by Tibetans. He is expecting to travel by train instead of on horseback.

Tibet covers an area of more than 1.2 million square kilometres or about one eighth of Chinese territory. It is the only provincial area in the country without an inch of railway.

About 90 percent of the 2.7 million Tibetan people live on farming or raising livestock. Poor traffic conditions have been one of the major obstacles for Tibet's modernization of Tibet.

People now travel to Tibet mainly by air or automobiles. Last year, more than 928,000 tourists visited Tibet.