Police are sealing off parts of two towns in China's Inner Mongolia in what residents describe as a kind of martial law after days of protests for ethnic rights triggered by the death of a Mongolian herder run over by a Chinese truck driver.

No protests were reported Saturday in the two county seats or in a nearby city where sporadic demonstrations took place this past week. Locals say police cordoned off the streets around government buildings, keeping people and vehicles away in a second day of what they called "martial law."

While China's troubled border lands of Tibet and Xinjiang are prone to communal strife, Inner Mongolia rarely erupts in protest. A rights group calls the latest protests the biggest in 20 years.