(Bloomberg) -- A surge in coronavirus cases in southeast Europe that included world tennis No. 1 Novak Djokovic has spread to the top of Serbia’s political sphere after the country held elections.

Authorities prepared to tighten lockdown measures Monday and opposition parties that boycotted the June 21 general ballot, partly in protest against the risk of spreading Covid-19, blasted the government for holding the vote.

The head of Serbia’s government office for Kosovo, the speaker of parliament and the defense minister all announced they’d tested positive, with the latter two having attended election-victory celebrations with President Aleksandar Vucic. Members of the electoral commission who handled ballots sent from polling stations were also infected, the Novosti newspaper reported.

The outbreaks come after more people stopped maintaining social distancing rules across the country, as well as the abrupt end to the exhibition Adria Tour, where players including Serbian tennis legend Djokovic and Bulgaria’s Grigor Dimitrov tested positive.

It also intensified scrutiny into the the landslide election victory of Vucic’s Serbian Progressive Party, which followed nationwide protests and accusations that his government had undermined conditions for a free-and-fair vote.

“Holding the fake elections and forcing citizens to participate, along with blackmail and threats, created additional risk with unforeseeable consequences for all Serbian citizens,” said the Alliance for Serbia, the biggest opposition group that boycotted the ballot.

Prime Minister Ana Brnabic dismissed the criticism and insisted that the surge in new cases reflects the deteriorating situation globally.

While Serbia’s government has no plan to reinstate the state of emergency, under which it imposed one of Europe’s strictest lockdown regimes, some cities -- including Belgrade -- will probably curb public gatherings, Brnabic told Pink TV.

There was no mention of possible restrictions that would postpone repeat voting in more than 200 polling stations where more than 200,000 people are expected to cast new ballots.

Serbia has avoided the high death tolls of other European countries such as Italy and the U.K. The Balkan state’s Health Ministry reported a near-record 254 new cases Sunday, bringing the total count to 14,046, with 270 fatalities.

Neighboring Romania, one of the worst-hit countries in the European Union’s east, has also witnessed a spike since June 15 after the government began easing restrictions. It reported 269 new cases Monday and 22 new fatalities, bringing the death toll to 1,634.

Health Minister Nelu Tataru said that the government is looking at increased tourism numbers in the mountains and the Black Sea coast and may impose travel restrictions to some areas. More easing, such as opening of restaurants from July 1, may also be delayed.

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