The coronavirus outbreak that began in the central city of Danang more than a week ago has spread to at least four factories in the city with a combined workforce of around 3,700, state media reported on Monday.

Four cases were found at the plants located at different industrial parks in the central city which collectively employ 77,000 people, the Lao Dong newspaper said.

Vietnam, praised widely for its decisive measures to combat COVID-19 since it first arrived in late January, is battling a new wave of the virus having gone more than three months without domestic transmission.

All but one of the four cases that media reported at the factories have yet to be included in the health ministry’s tally.

Vietnam on Monday reported one new case linked to Danang, a tourism hotspot, bringing its tally to 621 infections, with six deaths.

The new outbreak, the source of which is unclear, was first reported on July 25, and has reached at least 10 locations in the country, including Hanoi and Ho Chi Minh City, infecting 174 people and killing six.

One of the four factories has halted operations, Lao Dong reported, citing the chairman of the trade union of Danang’s industrial park management board.

Vietnam has carried out 52,000 tests for the coronavirus in the past seven days, according to a Reuters analysis of official data.

It said on Saturday it planned to test Danang’s entire population of 1.1 million people, part of “unprecedented measures” to fight the outbreak. The city imposed a lockdown last week, closing entertainment venues and banning movement in and out of the city.

Authorities said on Sunday that the strain of virus detected in Danang is a more contagious one, and that each infected person can infect 5-6 others, compared to 1.8-2.2 in the previous period.

Reuters