Tens of thousands of protesters have swarmed the streets of Minsk pressing for the resignation of Belarus’ authoritarian leader in what human rights activists described as the largest anti-government rally since late August.
More than 200,000 people took part in the demonstration in the capital, the Viasna human rights centre said.
They carried red and white flags and marched while chanting “go away” and “new election”, references to a disputed presidential vote that returned President Alexander Lukashenko to a sixth term and triggered almost daily protests.
Several subway stations were closed, mobile internet was not working and water cannons and armoured vehicles were seen in the centre of Minsk.
Rallies also took place in other cities in Belarus and police detained scores of people across the country.
A list of detained protesters released by the Viasna centre had over 130 names by Sunday evening.
Mass protests have rocked Belarus for more than two months, ever since the official results of the August 9 election gave Mr Lukashenko a landslide victory with 80% of the vote.
His main challenger, Sviatlana Tsikhanouskaya, got only 10% of the votes and refused to recognise the outcome as valid, saying it was manipulated.
The post-election rallies have posed a major challenge to Mr Lukashenko, who has run the country for 26 years and relentlessly suppressed opposition and independent media.
Early on, authorities tried to quell the unrest with mass detentions and police dispersing crowds with truncheons, stun grenades and water cannons.
According to human rights advocates, some 15,000 people have been detained in Belarus since the election and more than 100 of them were declared political prisoners.
But the protests continued despite the crackdown and police threatening to open fire on the demonstrators.
Ms Tsikhanouskaya, who is currently in exile in Lithuania after leaving the country in fear for her safety, threatened to call a nationwide strike for Monday unless Mr Lukashenko announced his resignation, released political prisoners and stopped the crackdown on protesters before then.
“The people’s ultimatum,” as Ms Tsikhanouskaya dubbed her demands, was the theme of Sunday’s rally.
In a statement from Vilnius, Ms Tsikhanouskaya expressed support for the protesters in Belarus and said the deadline for authorities expires at 11.59pm. local time on Sunday.
“If the demands are not met, Belarusians will start the national strike,” Ms Tsikhanouskaya said.