Beijing officials say the Chinese capital is in "wartime emergency mode" after more than 50 new coronavirus cases were linked to a seafood market over the weekend.
On Saturday, the Xinfadi market closed after six shoppers who had visited the center earlier in the week tested positive for the coronavirus. An estimated 8,000 market employees have been tested.
Before Thursday, Beijing hadn't seen any new coronavirus cases in nearly two months. Now officials are worried that a second wave is near.
At least 10 cities near Beijing have been placed under lockdowns and residents have been instructed not to travel to the capital. Sporting events and inter-provincial tourism have been suspended effective immediately.
Beijing health officials have said optimistically that the capital will not become a similar scene to Wuhan, where the coronavirus outbreak began.
There have been more than 7.8 million coronavirus cases worldwide and more than 431,000 deaths.