NANNING - The karst underground structure development and groudwater recession caused the land subsidence at a village in Southwest China's Guangxi Zhuang autonomous region since June 1, which had forced hundreds of people to evacuate, local authorities said Saturday.

Guangxi is in a traditional karst region. The karst underground structure development and groudwater recession led to the land sink, which hit the Tanluo village of Nanning city on June 1, 7 and 8, said Wu Fu, deputy head of the regional geological environment monitoring station.

A total of 355 students at Tanluo village have been evacuated after sinkholes opened up. Five wells were closed near Tanluo village after the land sink.