On Friday the Da Nang Center for Disease Control and medical staff in Son Tra District took samples from 362 people living in An Hai Dong and Man Thai wards.

Both real-time polymerase chain reaction (RT-PCR) and Elisa tests are being done.

Ngo Van Dinh Hoai, deputy director of the Son Tra District Medical Center, said there are some language barriers since most of the foreigners are from China, Japan, South Korea and Spain.

"City authorities will take samples from all foreigners living or stranded in the city," Hoai said.

Acting Minister of Health Nguyen Thanh Long said on Thursday that the biggest outbreaks, in Da Nang, Quang Nam and Hai Duong, have "basically been brought under control," with the number of new cases markedly dropping of late.

Da Nang authorities have decided to continue social distancing indefinitely, limiting gatherings to two people and household shopping to once every three days even as the city recorded 369 infections since July 25.

They have speeded up mass testing in high-risk areas.

The health ministry said the city has so far tested 86,000 people.

Vietnam’s Covid-19 count is now 1,009, including 25 deaths.