NINGNAN, Sichuan -- Four people have been confirmed dead after a rain-triggered mudslide hit a construction zone on Thursday morning in southwest China's Sichuan province.

The disaster occurred at 6:14 a.m. at the construction zone of Baihetan Hydropower Station of China Three Gorges Corporation in Ningnan county, Liangshan Yi autonomous prefecture, said Hu Bin, an official with the Corporation.

As of 9:00 p.m. Saturday, 36 people were still missing, said Hu.

The dead and missing are the hydropower station workers and their family members who were living in a three-story building.

Rescuers and work teams sent by local governments have rushed to and started to work at the mudslide-hit region.

The Baihetan Hydropower Station, currently under construction by the China Three Gorges Corporation, is located on the lower reaches of the Jinsha River, a major headwater stream of the Yangtze River, the country's longest waterway.

China's National Committee for Disaster Reduction and Ministry of Civil Affairs on Thursday jointly released a national-level emergency response to the Sichuan mudslide and sent work teams to the region.