Witnesses in Tibet say gunfire was heard in the capital of Lhasa Friday as a week of rare protests escalated and shops were set on fire in the center of the city.
The new reports of violence and clashes between police and protesters come as a series of rare rallies against Chinese rule have taken place in the remote region of China this week.
Tourists and other witnesses say fires were burning in the capital and report violence and chaos on the streets.
The U.S. Embassy in Beijing has issued an advisory to Americans warning them to stay away from the city. The Embassy says it has received first-hand reports of gunfire and other incidents of violence and warned U.S. citizens to stay inside until the situation is under control.
China's official Xinhua news agency says a number of shops were burned today in downtown Lhasa. It also reports that people have been taken to the hospital with unspecified injuries.
This week's protests in Tibet by Buddhist monks and others opposed to China's rule are the largest in nearly two decades.
A U.S.-based human rights group says Chinese authorities sealed off three monasteries in the Tibetan capital following this week's protests. The International Campaign for Tibet says the recent violence may be a sign that a growing number of Tibetans are unhappy with Chinese rule.
The protests come as Tibetan exiles held rallies across the globe earlier this week to mark the 49th anniversary of an uprising against Chinese rule in their homeland.
China blames Tibet's exiled spiritual leader, the Dalai Lama, for the protests.
Chinese troops took control of Tibet in 1951. At the end of that decade, the Dalai Lama and many followers fled the region and were allowed to settle in Dharamsala in India.