The new infection chain was identified Saturday, with the first case being a delivery person of Viettel Post company who lives in Luong Tai District and works at the firm’s local branch.

He had contracted the new coronavirus after contacting with several warehouse staff in Hanoi’s Bac Tu Liem District on Aug. 6 and developed symptoms last Friday.

By Monday, 21 people related to him in Bac Ninh, which borders Hanoi, have been confirmed positive.

The new cluster had ended a streak of 21 days without any new community infections for Bac Ninh.

Local authorities have tracked down 386 people having direct contact with the delivery man.

Luong Tai District with a population of 107,215 has been isolated from Sunday and it is expected that around 50,000 samples would be collected for mass testing to detect any possible infections.

The Ministry of Health has ordered Bac Ninh and Hanoi to expand their epidemiological investigations related to this cluster to quickly locate the infected people and areas to absolutely prevent infections from spreading into industrial parks.

Bac Ninh, home to many industrial complexes, including those of Samsung Electronics, used to be the second worst hit locality after its neighbor Bac Giang Province when the fourth Covid-19 wave first hit Vietnam in late April.

On June 30, the province with 1,746 cases had basically put its outbreak under control.

So far in the ongoing wave, Vietnam has recorded 270,986 Covid cases, with HCMC accounting for the most with 149,286.