XINING, May 31 (Xinhua) -- Authorities in northwest China's Qinghai Province have banned the releasing of exotic species at a major river source area.

According to a regulation passed Thursday by the provincial authorities, releasing of exotic species, artificially bred species or genetically modified species is strictly prohibited in public water resources in Yushu Tibetan Autonomous Prefecture.

Yushu is located in the southern part of Qinghai, where the three-river-source Sanjiangyuan lies. The area is home to the headwaters of three major rivers -- the Yangtze, Yellow and Lancang.

In recent years, there were several cases of local herdsmen and visitors to the area releasing carps and crucians into the water, threatening the water quality and the local eco-system.

The regulation is effective on July 1. Anyone that violates the regulation will be punished accordingly.