More than 2,500 people have been relocated in southwest China's Sichuan Province after a rain-triggered mudslide blocked a river and formed a barrier lake in the area, local authorities said on Tuesday.

The barrier lake on the Heishui River in Aba Tibetan and Qiang Autonomous Prefecture was formed late on Monday following torrential rain, according to officials with the prefecture government.

It is estimated that the barrier lake contains 400,000 cubic meters of water, imposing threats to people on the downstream.

No casualties were reported after the mudslide, although contact has been lost with one person, officials added.

The prefecture government has set up a disaster response center, and technicians and workers have been sent to the scene.

Heavy rain has battered various areas in Sichuan Province since early July, and the provincial weather bureau predicted that the region will see more of the same before July 15.