China has begun building a 13.3-billion-yuan (two-billion-dollar) extension to the world's highest railway line, which links Tibet to the rest of the nation, state media reported Monday.

The extension linking the Tibetan capital Lhasa to Xigaze -- the Himalayan region's second-biggest city -- should be completed in four years, the official China Daily said.

The building of the 253-kilometre (155-mile) line, which began on Sunday, is the first extension of the Qinghai-Tibet railway, which opened in July 2006, the report said.

Nearly half of the line will be laid in tunnels or on bridges, it added.

Chinese authorities see the railway as an important tool in modernising and developing the vast region.

However, critics say that the line is allowing the Han Chinese, the nation's majority ethnic group, to flood into Tibet, harming local culture and accelerating environmental degradation of the pristine region.

"The railway will detour around nature reserves and drinking water sources," Zhang Qingli, Tibet's Communist Party chief, was quoted as saying by the state-run Xinhua news agency.

"More measures will be taken during construction to better protect the fragile plateau environment."

Railways minister Liu Zhijun said the extension would play a "vital role in boosting tourism in the southwestern part of Tibet and promoting the rational use of resources along the line," according to the China Daily.

Authorities are also planning another extension from Lhasa to Nyingchi in the southeast of Tibet, the report said.

The railway climbs over a pass at 5,072 metres (16,737 feet) above sea level, making it the highest railway in the world.

earlier related report
Buffett says China carmaker BYD 'right choice for me'
Hong Kong (AFP) Sept 27, 2010 - US billionaire investor Warren Buffett said Monday that Chinese battery and auto maker BYD was the "right choice for me", two years after his Berkshire Hathaway bought a stake in the firm.

"BYD is the right choice of me, and I hope it's the right choice for you too," Buffett told hundreds of BYD car dealers at a company event in the southern industrial city of Shenzhen, Dow Jones Newswires reported.

Buffett described BYD as a "young and energetic" company, and said he was "amazed" by the performance of its E6 electric car.

In August, BYD chairman Wang Chuanfu said the company was on track to launch its electric car in the US market later this year, while the firm is also studying launching home-appliance products.

BYD organized a number of events that started Monday in three Chinese cities intended to showcase the company's advanced electric vehicle technology along with the launch of several new projects, in a major media drive that coincides with Buffett's visit, Dow Jones said.

MidAmerican Energy Holdings Co., a unit Berkshire Hathaway, bought its stake in BYD in 2008 for 230 million US dollars. It owns about 9.89 percent of BYD.

In August, BYD said it hoped to list on the Shenzhen Stock Exchange in the second half of the year, after delaying earlier plans for a mainland listing.

The company has said it plans to offer up to 100 million A shares to raise 2.85 billion yuan (425 million US dollars).