BEIJING, Oct. 12 (Xinhua) -- Chinese authorities on Friday initiated a national emergency response to a landslide which caused the formation of a barrier lake in the border area of Sichuan Province and Tibet Autonomous Region in southwest China.

The China National Commission for Disaster Reduction and the Ministry of Emergency Management jointly activated a level-IV emergency response, the lowest level, on Friday at 3 p.m., the ministry said in a statement.

The landslide struck at about 7 a.m. Thursday in the border area of Sichuan and Tibet, forming a barrier lake near a section of the Jinsha River.

By 2 p.m. Friday, more than 21,000 people had been relocated in Sichuan and Tibet, according to local authorities.