Dozens of cases are linked to the Xinfadi wholesale market, one of Asia's biggest.

The city's government rushed to shut down the sprawling complex, which supplies nearly 90 percent of Beijing's fresh seafood, vegetables and fruit.

(Speaking in Mandarin) We were told last night that this place is closed.

(Speaking in Mandarin) Now I can only sell my peaches on the street.

(Speaking in Mandarin) There have been very few people buying them, so I'm going to be at a loss for sure.

(Speaking in Mandarin) But what can you do?

(Speaking in Mandarin) Life and health always come first.

The market is in the southern district, home to more than two million people, an area that is now under a strict lockdown.

Plans to open kindergartens and primary schools on Monday have been delayed.

Sports and athletic events have been postponed, while public facilities have shut down, and movement in and out of the city is restricted.

State media says the virus was initially detected on a cutting board used to prepare imported salmon, prompting supermarkets to take the fish off their shelves.

Additional tests found that the virus could be carried and spread through produce and packaging, meaning it could have traveled well beyond the city's limits.

Cases linked to the market have been confirmed in two other provinces.

Beijing's government has launched an extensive operation to test 10,000 workers from the market, and screen anyone who visited it this month.

(Speaking in Mandarin) There was panic in the first wave, but there's no need for that in the second wave.

(Speaking in Mandarin) People are vigilant.

(Speaking in Mandarin) We have big data and the government can strictly control things.

(Speaking in Mandarin) There should be no problem.

Beijing downgraded its emergency response level only a week ago, easing restrictions on wearing masks and having temperature checks.

This latest cluster is raising concerns due to parallels with Wuhan city, where the virus was first discovered last year.

It too started at a market, and led to months of lockdowns until China said it had overcome the outbreak in March.

The hope is that that declaration wasn't premature.

Divya Gopalan Al Jazeera, Hong Kong.