China is allowing foreign diplomats, including an American, to visit Tibet's capital today and tomorrow.
The trip to Lhasa comes even as police close off the Muslim quarter. The action comes two weeks after Tibetan rioters burned down the city's mosque amid the largest anti-Chinese protests in nearly two decades.
It's not clear why the area has been sealed off. But rioters have prominently targeted businesses belonging to Chinese Muslim migrants.
The protests were the longest challenge to China's rule in the Himalayan region since 1989. The ensuing crackdown has focused international attention on China's human rights record in the runup to the Summer Olympics.