The Duttabad area along EM Bypass, which borders parts of Purbachal Housing Complex in Salt Lake, was sealed on Saturday after a 39-year-old man with Covid-19 symptoms was admitted to hospital.

The man lives with at least eight family members. None was taken to a quarantine centre till late on Saturday, an official of the Bidhannagar Municipal Corporation said.

Police teams blocked nearly all lanes and bylanes with guardrails or inter-linked bamboo poles to ensure no one steps in or out without a genuine reason.

An officer of the Bidhannagar Police Commissionerate said they had sealed the area because almost all household help in adjacent areas in Salt Lake stay in Duttabad and many of them were going to work despite the lockdown.

The sealed-off zone has tenements standing cheek by jowl. There are more than 10,000 single and two-room dwelling units, where more than 50,000 people live.

Duttabad has a number of community toilets and taps where crowds gather. “It is difficult to maintain social distancing norms at these points,” a civic official said.

On Saturday afternoon, Metro spotted a large number of men and women sitting or standing close to one another, waiting to fill containers with water from roadside taps. Swapan Mondal, a carpenter, said they had no option but to mill around the tap. “This tap serves at least 100 families. We have no option but to come here and collect water,” he said.

Local councillor Nirmal Dutta said he had asked neighbourhood clubs to help distribute food and essential items to the residents of Duttabad.

An officer of the commissionerate said they were facing an uphill task trying to prevent people from leaving or entering the pocket.

“Most are not listening to our warnings. At times people are ganging up and trying to surround us,” said an assistant sub-inspector.