The city Center for Diseases Control said 54 places including supermarkets, convenience stores, hospitals and hotels in the city buy beef from Thanh Nga Supply Foods where at least 49 employees tested positive.

Its delivery staff visited these places between July 26 and 30, staying there for 30 minutes to two hours as their goods were checked, it said.

It has exhorted people who visited these places in the last two weeks to contact medical centers immediately.

The list includes four hotels Pullman Hanoi, Daewoo Hanoi, Lotte, and Novotel Duy Tan, all in the city’s downtown.

On Tuesday a kitchen worker at Pullman who had been in close contact with a beef delivery person tested positive.

A source of Daewoo said that following the city's Covid-19 social distancing order, the hotel has stopped receiving new guests since July 28 after hosting deputies of the National Assembly session. Its bakery, apartment and office sectors are still in operation with pandemic prevention measures.

Hanoi has had 1,668 local cases in the fourth Covid wave that began in late April, with a number of new clusters being detected in the past week.