Yaks are seen on land covered with snow in Nagqu, southwest China`s Tibet Autonomous Region, Nov. 12, 2011. (Xinhua/Wen Tao)

Due to the snow in Nagqu during the evening on Nov. 11, part of the road linking Xining in Qinghai Province and Lhasa in Tibet was covered by ice.

Yaks are seen on land covered with snow in Nagqu, southwest China`s Tibet Autonomous Region, Nov. 12, 2011. (Xinhua/Wen Tao)

A truck moves on a road covered with ice in Nagqu, southwest China`s Tibet Autonomous Region, Nov. 12, 2011. (Xinhua/Wen Tao)