The presidential election was marked by a crackdown on opposition candidates and widespread anti-government protests.
Police and protesters clashed after authorities in Belarus said longtime authoritarian leader Alexander Lukashenko had likely won the presidential election.
Belarus' central election commission said incumbent President Lukashenko was ahead in five regions with around 82 per cent of the vote after a tense election marked by a crackdown on opposition candidates and widespread protests.
Honest People, an independent association in Belarus that monitors elections, said it found 5096 violations from observers.
They also called into question the election commission's reported turnout statistics. The group said about 70 election observers were detained.
As polling stations closed, multiple internet providers lost routing, according to internet watchdog Netblocks, which said the internet disruption was widespread.
Most of Minsk had been shut down by police and military, likely in an effort to avoid protests.
Several Belarusian telegram channels reported that at certain polling stations, main opposition candidate Svetlana Tikhanovskaya was ahead of Lukashenko.
Earlier in the day Lukashenko reportedly warned opposition protesters, stating: "if you're going to go against our country, or even in the smallest way try to plunge the country into chaos and destabilise it, you will receive an immediate response from me," according to AP.
Polls closed in Belarus at 19:00 CET but voting continued as people were still queuing in the capital city, Minsk. Photos showed people queuing outside polling stations, which authorities blamed on opposition political strategists.
On the eve of election night, authorities detained the campaign manager of main opposition candidate Tikhanovskaya, who only became a candidate after her husband was jailed.
Another person close to the campaign, Veronika Tsepkalo, fled for Moscow.
The Central Election Commission in Belarus said that there was 79 per cent turnout by 6:00 pm CET.
The head of the election commission Lidia Yermoshina called on the losing presidential candidates to accept defeat calmly, to congratulate the winner and not "agitate" the masses.
Official results are expected to be announced on Monday for the first round of the election. A candidate must receive more than 50 per cent of the vote to win outright in the first round.
But experts expect that the election will be called for Lukashenko despite the actual results.
Checkpoints were placed around Minsk's main road intersections and government buildings are being fenced off as protests might take place later during the day.
Several potential opposition candidates were barred from running - most notably, Victor Babariko, who was arrested amid fraud charges, and Valery Tsepkalo, after some signatures he collected were invalidated by the electoral commission.
International observers are also concerned about the fairness of the electoral process after the OSCE's Office for Democratic Institutions and Human Rights (ODIHR), an international body that assesses the fairness of elections, announced it was pulling out of a planned mission to the eastern European country due to a late invitation by the Belarusian authorities, leaving, according to experts and human rights activists, no credible observers overseeing the election.
Observer group Honest People told Euronews more than people have been detained since the voting began in the country.