China has begun construction work on a strategic two billion US Dollar rail network to connect the Tibetan capital Lhasa with the region's second largest city of Xigaze that borders India, Bhutan and Nepal. The head of China's National Reform and Development Commission, Zhang Ping, said in Beijing on Monday that the extension of the 253-km railway line will take four years to complete. Xigaze city, besides being the home of Panchen Lamas, the second highest Tibetan spiritual head of Tibetan Buddhism, is also famous for its proximity to Mount Everest which virtually rises up from it.