Witnesses and foreign media have reported a huge buildup of Chinese troops in areas with large Tibetan populations, as the government cracks down on an unprecedented wave of protests.
Foreign media report seeing troop convoys with hundreds of vehicles moving by road and rail into Tibet on Wednesday and Thursday. Witnesses report a heavy security force buildup and roadblocks in Tibetan areas in the adjoining provinces, including Yunnan, where no protests have been reported.
In Lhasa, Chinese authorities forced the last known foreign journalist in the Tibetan capital to leave Thursday. German correspondent Georg Blume reported seeing thousands of security personnel on the streets of the city carrying out house-to-house searches.
Beijing acknowledged Thursday for the first time that protests have spread from the Tibet Autonomous Region to nearby provinces where more than half of China's Tibetan population lives.
China's official Xinhua news agency says police shot and wounded four rioters in a Tibetan area of Sichuan province earlier this week. It says police opened fire in self-defense.