A Chinese coal driver has been sentenced to death for killing a Mongolian herder in a case that sparked weeks of unrest across Inner Mongolia.

China's official Xinhua news agency said the sentence was handed down Wednesday after a six-hour trial in the Chinese autonomous region. The court found that driver Li Lindong killed the herder, named Mergen, by hitting him with his truck and dragging him 145 meters to his death.

Lu Xiangdong, another Han Chinese who had been riding in the truck with Li, was also found guilty of murder and sentenced to life in prison. Two other Chinese who prevented police from pursuing the truck were sentenced to three years in prison for obstructing justice.

Mergen was hit while he and about 20 other herders were blocking a road to protest noise and dust caused by coal miners in their village. The killing sparked protests that sent thousands of students into the streets of the regional capital, Xilinhot.

The quick arrest and trial of the Chinese mine workers reflects the government's anxiety to avoid ethnic tension in Inner Mongolia of the kind that has long troubled Tibet and western Xinjiang province.

The government has promised to address the legitimate grievances of herders in the region.