Belarusian demonstrators flooded the streets of the capital Minsk on Sunday, the final day of an ultimatum set by the opposition for the embattled strongman leader to resign after months of mass protests.
Videos taken by bystanders that were circulated by local media showed a convoy of buses carrying security personnel to the city centre along with metal cordons.
A dozen metro stations in the centre of Minsk were closed to deter demonstrators from gathering and mobile internet was restricted.
Exiled opposition leader Svetlana Tikhanovskaya this month gave President Alexander Lukashenko a deadline of two weeks to resign, halt violence and release political prisoners, warning he would otherwise face a crippling general strike.
The 38-year-old political newcomer fled Belarus after claiming victory in an August presidential election that handed Lukashenko, 66, a sixth term and she has been rallying support from European leaders and calling for new elections.
During a visit to Copenhagen on Friday to meet Danish Foreign Minister Jeppe Kofod she called for a repeat ballot "as soon as possible," and in separate statement said a date for the vote must be decided by the end of the year.
Yet she also conceded that it was unclear how many Belarusians would answer the call for a general strike Monday, with many people anxious about government intimidation and dismissal from positions at state-run enterprises.
"I know a lot of people are afraid to lose their jobs," she told AFP.
"We're not organising the strikes ourselves, it's people themselves who decide if they're ready or not."
'The last day'
The Poland-based Nexta Telegram channel, which has been mobilising recent post-election protests, called on its two million followers to gather at 2 pm (1100 GMT) in the centre of Minsk.
"It is time to return the law, development, fair elections and a full set of civil rights to Belarus," Nexta wrote, days after it was deemed "extremist" by a court in Minsk.
"The last day of the People's Ultimatum has gone."
After an initial police crackdown on post-vote demonstrations that resulted in thousands of detentions and allegations of torture in prisons, the authorities warned this month they would sanction the use of live ammunition to disperse protesters.
But anti-Lukashenko demonstrators continued to congregate in cities throughout the country despite the threat, with tens of thousands gathering each weekend.
Several hundred women marched through Minsk on Saturday to protest against Lukashenko, with reports of detentions.
Plans for a pro-government rally were binned on Friday, officials said, ostensibly over safety concerns and difficulties ensuring transport for Lukashenko supporters coming from the regions.
Wave of sanctions
The EU and Western countries have slapped a wave of sanctions for vote-rigging and police violence on allies of Lukaskenko, who has leaned heavily on support from staunch ally Russia in the unrest.
Russian President Vladimir Putin during the peak of the political instability promised Lukashenko a $1.5 billion loan to bolster the struggling economy and offered the support of his security services if the instability deteriorated.
US Secretary of State Mike Pompeo spoke by phone with Lukashenko on Saturday to call for the release of a high-profile American political strategist who was detained in Belarus ahead of the vote.
Vitali Shkliarov, a Harvard University fellow who has advised presidential candidates in the United States, Russia and Ukraine was released under house arrest earlier this week.
The European Parliament on Thursday awarded the Sakharov Prize for human rights to the movement opposing Lukashenko.