An area is quarantined for treating Covid-19 patients at Da Nang General Hospital in Da Nang, central Vietnam, February 2020. Photo by VnExpress/Nguyen Dong.

The patient works at an outlet in the Dien May Xanh electronics supermarket in Hai Chau District, Da Nang. She received the British tourists at around 6-7 p.m. on March 4. The tourists were confirmed Sunday as Vietnam's 22nd and 23rd Covid-19 infections.

She talked to the tourists for 10-20 minutes as they wanted to buy cell phone SIM cards. During the conversation, she pulled down her face mask while the tourists did not wear any.

The Da Nang woman was placed in quarantine at the Da Nang General Hospital Wednesday after her samples sent to the Pasteur Institute in Nha Trang tested positive for the novel coronavirus.

She became Vietnam's 35th patient and one of 19 active cases, all but three related to a Vietnam Airlines flight from London to Hanoi on March 2.

13 passengers on the flight have now been confirmed as infected, the first being Nguyen Hong Nhung, a 24-year-old Hanoian. Of the others, 10 passengers are British tourists including the two in Da Nang, one is an Irish man, and one a Hanoi man.

The foreign tourists have traveled to many places in the country, including Sa Pa and Ha Long in northern Vietnam, and Hue and Hoi An in central Vietnam.

Nhung's personal chauffeur and an aunt have also been infected.

A 24-year-old Vietnamese woman who had met Nhung at a party in London last month before falling sick and being put on a private plane to Saigon on Monday tested positive the same day.

The two other cases are a Vietnamese man returning from Daegu, South Korea, and a Vietnamese businesswoman returning from the U.S.

The Covid-19 outbreak has thus far spread to 119 countries and territories around the world, killing over 4,200.