Beijing carried out mass coronavirus tests on Sunday after a new outbreak in the city, triggering travel warnings across the country for fear of the disease coming back.
The deadly contagion in China had been largely brought under control by stringent barriers that were imposed earlier this year but have since been lifted.
But a new cluster associated with a food wholesale market in the capital has raised widespread concern and sparked the specter of a return to painful restrictions.
The National Health Commission (NHC) reported 57 new infections on Sunday, 36 of which were local broadcasts in Beijing, all related to the Xinfadi market.
Another two domestic infections were in the northeastern province of Liaoning and were in close contact with the cases in Beijing.
The 19 other infections affected Chinese nationals who returned from abroad.
Liaoning was one of several provinces that the new outbreak was to discourage residents from traveling to Beijing – along with cities like nearby Tianjin and several in the Hebei province that surrounds Beijing.
Some local authorities said that people entering Beijing must be quarantined, state media reported.
In the capital, a very small part of the city has been closed, including 11 housing estates near the market, which supply most of the city's fresh produce.
Officials said on Sunday they wanted to run virus tests on 46,000 residents in the area around the market and had set up 24 test stations.
Everyone who works at Xinfadi must also take a test.
So far, 10,881 people have been tested in the region, with a further eight cases diagnosed on Sunday. They were not included in the NHC list earlier on the day of the past 24 hours.
"I went to the Xinfadi market to confirm that I am not infected," a 32-year-old woman with the last name Guo told AFP as she lined up in a scorching heat in a stadium waiting for a virus test.
"We were told that after the tests … if it was positive, we would be taken straight to the hospital."
Locks and closings
One of the new cases on Sunday was a 56-year-old man who works as an airport bus driver and visited the Xinfadi market in early June before becoming ill later, the state-run Volkszeitung reported.
The meat section of the huge, sprawling market was closed on Sunday, and AFP reporters saw hundreds of police and security personnel and dozens of paramilitary officers blocking access.
Efforts to track down those who have visited the market have begun. Businesses and neighborhood communities have asked employees and residents across the city about their recent movements.
A vegetable market next to Xinfadi was open on Sunday, and trucks arrived to deliver or collect goods.
"Scared? Not really," a delivery agent named Zhang told AFP.
"But still I have no choice – I'm part of the lowest class in society. So I have to keep working to make a living."
In the nearby streets, the residents were closed and the restaurants closed.
Some people used a wooden step ladder that was leaning against a church entrance to share supplies with loved ones.
A resident with the last name of Chen told AFP that he had made several trips by car to the front gate of his property to deliver groceries.
"Once I've delivered the supplies to my family members, I'll go upstairs to join them," he said.
"I can't get out after that."
COVID-19 first appeared late last year and one of the first clusters came from a market in downtown Wuhan selling wild animals for meat.
The recent outbreak in Beijing has focused on hygiene in the city's food supply chain.
State media reported that the virus was found on cutting boards for imported salmon and that large supermarkets had removed the fish from their stocks.
The Beijing authorities ordered a city-wide food safety inspection that focuses on fresh and frozen meat, poultry and fish in supermarkets, warehouses and catering services.
A retailer with the surname Sun selling tomatoes and cherries at a central grocery store told AFP that there were fewer customers than normal.
"People are afraid," he said.
The city council has closed nine schools and kindergartens near Xinfadi, while sporting events and cross-province tour groups have ceased.
(Except for the headline, this story was not edited by NDTV staff and published from a syndicated feed.)