Southwest China's Yunnan Province reported six confirmed and 23 asymptomatic COVID-19 cases on Wednesday, all in Ruili City, said local health authorities on Thursday.

As many as 105,530 samples had been collected as of 8 a.m. Thursday, as the border city finished sampling work for mass nucleic acid testing for all its residents.

A total of 1,320 close and casual contacts were identified and lodged at eight designated hotels for collective medical observation.