Within just four days 110 people with Covid-19 have been found in two alleys in Thanh Xuan District, Hanoi, making it the city’s most dangerous cluster.

Authorities have locked down alleys 328 and 330, Nguyen Trai Street in Thanh Xuan Trung Ward and tested all their residents. Ten out of 11 wards in Thanh Xuan District have reported cases so far.

Medics call on a household to do tests for Covid. Both alleys are small and densely populated -- there are 700 households with 2,000 people -- and that could be the reason for the high infection rate, authorities said. They would be blocked until August 30 until testing and contact tracing are completed, and Thanh Xuan District would decide on further isolation based on developments, its chairman, Vo Dang Dung, said.

Everyone in Thanh Xuan Trung Ward was tested for a second time on Thursday. The tests will be done in the ward every three days since it is now considered a high-risk zone. Anyone refusing to give samples will be sent to quarantine facilities.

Dozens of medics have been dispatched to Thanh Xuan Trung to speed up testing and isolate patients. Local authorities said the outbreak began from a vegetable vendor who usually visits the Nga Tu So wholesale market in Dong Da District.   Hanoi’s Center for Disease Control and Prevention has suggested testing all vendors at the market.

A family being sent to quarantine since they were in direct contacted with Covid patients.

A man in a raincoat, mask and face shield in Alley 330, who came to get a package he had ordered, is told to get back inside his house.

An alley on Nguyen Trai Street that links the two alleys of 328 and 330 is blocked.

Soldiers help local personnel guard the two alleys.

Volunteers and local task forces deliver food and other essential items to people under lockdown at the two alleys.  In the ongoing Covid wave, which began four months ago, Hanoi has recorded more than 3,000 cases.