HOHHOT -- Authorities in North China's resource-rich Inner Mongolia autonomous region halted 467 illegal mining projects last year in a region-wide overhaul mainly aimed to ensure work safety and environmental friendliness of the mining sector, officials said Saturday.

The regional land and resources bureau checked about 9,000 mining projects in the months-long overhaul, halting 467 illegal projects, ordering 887 mines to suspend operations and permanently shutting down 73 mines.

Officials of the bureau said the mines either were unlicensed, harassed the life of local residents, or failed to properly compensate for the use of grassland.

In a bid to build "harmonious mines" the government defused 100 disputes between local herders and mining companies last year while establishing an effective mechanism among the government, mines, and local residents to settle mining disputes through dialogue, they added.

Inner Mongolia ordered an overhaul of the mining sector, originally scheduled for one month but was extended, after protests against grassland mining broke out last May in the wake of the death of a Mongolian herder during a dispute between miners and herders.

The regional coal mine industry bureau promptly ordered local work safety watchdogs to strengthen supervision of coal mines to ensure safe production practices, protection of the environment, and attention to the welfare of local residents.

Inner Mongolia holds the country's largest coal reserves -- 770.3 billion tons by the end of 2011 -- and rich deposit of other mines such as iron ore and rare earth metals.

A mining boom in recent years has brought prosperity to the region but concerns have been raised on the ecological damage that mining might cause to a region better known for its stretching, wavy grassland and a unique herding culture.