Medical staff guide residents at a nucleic acid testing site in Qingdao, east China's Shandong Province, Oct. 14, 2020. (Photo:Xinhua)

Two Myanmar nationals tested positive for COVID-19 when staying in quarantine at a designated location in Mengding town of Southwest China's Yunnan Province, the Yunnan authority announced on Monday. They were diagnosed as asymptomatic cases and epidemiological investigations are underway.

All the close contacts of the two cases have been put under quarantine at designated locations for medical observation. The relevant places have also undergone disinfection, according to the authority.

All the residents in the residential quarter where one of the cases lives have returned negative nucleic acid test results.

Moreover, 66 schools in the town have been suspended. All school faculties, students, and parents are required to take nucleic acid tests and subject themselves to temporary home isolation.

Residents in three key areas of Mengding have been asked to stay in home isolation from Monday through to November 23 as well. During the isolation period, all businesses, except for supermarkets, pharmacies, wet markets and restaurants, will be closed. Restaurants are not allowed to provide dine-in meals as well, the authority said.

All vehicles, except for those used for daily necessities, epidemic control, and medical treatment are not allowed to enter or leave these areas from Tuesday.

The two cases were found in a nucleic acid testing plan covering over 78,000 people in the three areas of Mengding carried out from Monday, after Yunnan reported one imported asymptomatic case from Myanmar on November 7.

The case, a 22-year-old Myanmar woman, went to Mengding from Myanmar, and returned positive nucleic acid test results on November 6.

As of 10 pm on Monday, 66,685 samples have been collected in the testing which is planned to be completed by Tuesday.

Mengding town is located in the southwestern part of Yunnan Province, bordering Myanmar to the west.