Of the 82 new patients, 72 work at Vietnam Poyun Electronics Co., Ltd. in Hai Duong Province and 10 at Van Don International Airport in Quang Ninh Province, both in northern Vietnam.

They had come into close contact with patients 1552 and 1553 that were diagnosed on Thursday morning.

The former is a 34-year-old woman working for Vietnam Poyun and the latter is a 31-year-old man who works at the airport.

The woman, a resident of Hung Dao Commune in Hai Duong Province's Chi Linh Town, had come into close contact with a colleague who tested positive for the virus upon arriving in Japan last week.

It is known who was infected first or by whom.

Hai Duong health authorities have begun contact tracing.

Van Don airport has been receiving repatriation flights with a number of people with Covid arriving on them.

The infected went to a local hospital after developing fever, cough and sore throat, and tests showed later he had Covid.

The airport has been locked down.

Chairing an urgent government meeting, Prime Minister Nguyen Xuan Phuc called on Hai Duong and Quang Ninh provinces to swiftly track down everyone who came into contact with the clusters and temporarily close their borders to prevent people from leaving.

In two weeks Vietnamese will celebrate their biggest festival of the year, the Lunar New Year, an occasion for family reunions that will see millions travel home.