The outbreak was one of several surges of infections in the central European country of 10.7 million people.

Public health officials have brought back restrictions on public activities in some areas including the industrial north-eastern region that is home to 10% of the population.

The country reported 247 new cases on Wednesday, the highest number since a spike in late June, prompting Prime Minister Andrej Babis to say that face masks may be made obligatory again in selected indoor spaces.

Authorities suspect one woman with no symptoms was the source of the infection at a July 11 birthday party at the downtown Prague Techtle Mechtle club.

The Prague Public Health Authority said 68 visitors to the club, seven employees, and 23 family members and contacts have tested positive. Another 273 others have been put in quarantine.

Following media reports that some of the visitors got infected by sharing a drink with one straw, hygienists urged people to keep social distancing.

“The Prague Public Health Authority emphatically recommends that everyone consumes their drink solely from their own glass and avoids consumption from a common container,” it said in a statement.

Despite the growth in daily cases in the past several weeks to Wednesday’s total of 14,570, the number of those hospitalized has grown only slightly to 141, just one third of the number during a peak in April.

The country has reported 364 deaths from the disease caused by the coronavirus, a fraction of the toll in more severely hit west European nations.

The public health service did not name the sports clubs affected by the nightclub outbreak, but major soccer clubs Sparta Prague, Bohemians 1905 and Dukla Prague have said they had infections in their reserve or junior teams.

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REUTERS