Authorities in Chinese capital Beijing on Tuesday restricted travel, closed all sports and entertainment sites and ramped up testing after a city official warned that the coronavirus situation is “extremely severe”, AFP reported.

The Beijing Municipal Health Commission reported 27 fresh coronavirus cases, taking the last five-day total to 106. Most of the cases were linked to the Xinfadi seafood supermarket in Beijing’s southern Fengtai district. The wholesale market was closed on June 13 after it was identified as being at the centre of a new cluster of cases. However, Xinfadi is more than 20 times larger than the seafood market in the city of Wuhan, where the outbreak originated late last year. The size and number of people who work or visit there from in and outside of Beijing has sparked fears of a new wave of the infection.

“The epidemic situation in the capital is extremely severe,” Xu Hejian, a spokesperson for the Beijing city government, said at a press briefing. On Sunday, he had said Beijing had entered “an extraordinary period”.

Meanwhile, authorities have put almost 30 communities in the city under lockdown and the testing capacity has been expanded to 90,000 a day. Residents were advised to avoid crowds and gathering in groups for meals. Security checkpoints have also been set up at residential compounds.

Officials also said that they had disinfected 276 agricultural markets and 33,000 food and beverage businesses. Over 8,000 workers in the Xinfadi market have been tested and sent for quarantine.

The World Health Organization had also expressed concern about the market cluster, pointing to Beijing’s size and connectivity. The city had reported no new cases for 56 consecutive days before a cluster of diagnoses began last week. Several other Chinese cities also warned residents against non-essential travel to the capital and imposed quarantine requirements on visitors from Beijing.

Follow today’s live updates on the coronavirus pandemic here.