The US embassy in Beijing issued a warning Saturday against travel to Tibet

The situation in Lhasa continues to be unstable and Americans are advised to defer travel to Tibet at this time," it said in a statement on its website.

"In addition, Americans are advised to use caution when traveling to predominantly Tibetan areas of neighboring provinces, including Yunnan, Sichuan, Qinghai, and Xinjiang provinces.

"There have been reports of some demonstrations in provinces bordering Tibet, but no reports of violence that we are aware of."