Tibet, which China considers part of its territory, has also seen problems.
Demonstrations marking the anniversary of the failed 1959 Tibetan uprising against Chinese rule resulted in the killing of numerous demonstrators. Chinese authorities claimed a low number of deaths, while Tibetans and international media, a higher number.
The Chinese government crackdown has included closing off the country to the outside world and shutting out or controlling most media, including Internet media and sites used to show video footage of what happened. The military and police presence has also swelled.
There have been protests in the past in Tibet, such as in 1987 and 1989, but these were only in the capital, Lhasa, and involved mostly monks, intellectuals, and students. In contrast, the 2008 riots have spread to other parts of Tibet and included peasants and workers.