A Chinese truck driver has killed an ethnic Mongol herder who was trying to protect his grazing land, a rights group said, five months after a similar incident sparked protests in Inner Mongolia.

The vast northern Chinese region saw a wave of demonstrations in May sparked by the killing of a protesting Mongol herder and fuelled by resentment over Chinese rule and rapid exploitation of the area's rich natural resources.

On Sunday, the US-based Southern Mongolian Human Rights Information Centre (SMHRIC) said the Chinese driver of a fuel truck had hit and killed another herder on October 20 near the city of Ordos.

Authorities in Ordos said the death of the herder, named Zorigt, was an accident, and that the truck driver had been detained.

However, SMHRIC said there had been a number of conflicts between Chinese drivers and Zorigt and other herders, who the group said had been beaten and hospitalised several times previously.

Zorigt and other Mongolian herders were trying to "protect their land and livestock from unregulated Chinese oil and gas transport trucks that drive roughshod through their grazing lands and kill livestock," it said.

The recent confrontations between China's dominant Han ethnic group and the Mongol minority have laid bare simmering discontent in Inner Mongolia, a vast region of plains and deserts that separates China from the country of Mongolia.

In June, a court sentenced a coal truck driver to death after he ran over and killed another ethnic Mongol herder, in the incident that triggered widespread protests in the region.

The victim and other Mongols -- fed up with an influx of mining companies intent on reaping the region's rich coal reserves -- had attempted to block a number of coal-hauling trucks.

Many Mongols complain that Chinese culture is swamping their way of life.

In particular, a Chinese government policy to move traditional Mongol herders off the steppe to preserve the grassland ecology is widely considered a pretext to seize lands holding coal and other minerals.