More police officers have been assigned to patrol the Kekexili nature reserve on the Qinghai-Tibet Plateau in western China to guard against poaching and illegal mining.

Fifteen officers and four new stations have been added to the reserve's law enforcement contingent, which is responsible for social security at the reserve, which covers some 45,000 square kilometers. Their main mission will be to guard against poaching and illegal mining.

The mountain patrol officers in Kekexili have found no poachers since 2006, and the number of Tibetan antelope in the reserve, which used to be a favorite target of illegal hunters, has increased to 120,000, according to an earlier report by the Xinhua News Agency.

The crackdown on illegal mining by the reserve's administration office in 2000 also helped end poaching after access roads into the reserve were blocked, said Xinhua.

The administration has conducted regular patrols where they have seen an increase in the population of wild animals, including the nationally protected Tibetan antelope, Tibetan gazelle and wild yak.

However, an environmentalist, Wu Zhu, who has worked in Kekexili since 2005, said enhancing police presence won't address illegal mining, which he claims is still going on.

"Corrupt officials turn a blind eye to the mining and patrol officers often make detours to avoid inspecting the mining areas," alleged Wu, adding that some officials were even directly involved in mining for gold.

Illegal mining first started during the 1980s.

The reserve's administration office could not be reached as of late Thursday.