A massive landslide occurred in an eastern Chinese town Monday night, causing six or seven apartment buildings to collapse and burying an unknown number of residents, local authorities said Tuesday.

The accident took place at about 10:30 p.m. in Pengxi Township, Taishun County of Wenzhou City in Zhejiang Province, when the unexpected landslide soon destroyed the 4-story apartment buildings at the foot of a mountain, rescuers said.

Rescuers have pulled six people alive from the debris, but one of them is in critical condition.

It is not immediately known how many people were buried, rescuers said, adding that it is very difficult for them to carry out search operation due to a huge amount of mud and rock.

The landslide was triggered by continuous torrential rain brought by Typhoon Morakot, which has left six people dead and three others missing on the Chinese mainland after a powerful landing in east China Sunday.

More than 8.8 million people in Fujian, Zhejiang, Jiangxi and Anhui provinces were affected by Morakot, which forced local authorities to relocate 1.4 million people, the Ministry of Civil Affairs said late Monday.

It toppled more than 6,000 houses and inundated 387,300 hectares of cropland, the ministry said. Direct economic losses have amounted up to 9 billion yuan (1.3 billion U.S. dollars), it said.