Police in Belarus on Sunday detained more than 500 people during the latest in weeks of unprecedented demonstrations against President Alexander Lukashenko, as the opposition reached out to US President-elect Joe Biden.

For three months running, tens of thousands have taken to the streets of Belarus on Sundays to protest against the disputed reelection of Lukashenko, who has been in power for more than two decades.

His opponents are demanding he hand power to Svetlana Tikhanovskaya, a political novice who ran for president against Lukashenko on August 9.

Several thousand protesters, many carrying the red-and-white opposition flag, joined a march in central Minsk on Sunday.

Police vans and water cannons were deployed to the centre of the city with police sporadically detaining protesters in various locations.

Journalists working with AFP saw a heavy security presence, with baton-carrying riot police in black balaclavas grabbing protesters and taking them to police vans.

Local human rights group Viasna said that at least 516 people had been detained in the capital Minsk and other cities.

Olympic decathlete Andrei Kravchenko and the 2008 Miss Belarus pageant winner Olga Khizhinkova were among those detained, according to the Tut.by news website.

Pensioner Yelena Vasilyevich told AFP that she was taking part in the Sunday protest with her family and friends.

"I want to finally live in a free and democratic country,” said Vasilyevich, 65.

From exile in Lithuania, Tikhanovskaya said protests would continue "until victory” and that the past 90 days had shown authorities they had "lost legitimacy and power”.

"The regime doesn’t want to give us the right to decide what will happen next to our country,” she wrote on her Telegram channel on Sunday.

‘Stolen elections’ 

Tikhanovskaya, 38, says she was the true winner of the presidential poll and has gained the support of several Western leaders, who have refused to recognise the election results.

On Saturday she congratulated Biden and said she hopes to meet with the newly elected president.

"This was a real race of ideas, programmes and teams, unlike Belarus, where votes at elections were simply stolen, in the United States the vote of every voter was taken into account,” she said.

She said she believed Biden will "soon meet with the fairly elected president of the new, free Belarus”.

Democrat Biden has previously voiced support for the Belarusian opposition and promised he would expand sanctions against the regime.

Lukashenko on Saturday called the US vote a "mockery of democracy” and said he didn’t expect relations with Washington to change whatever the election outcome.

Apart from the large-scale Sunday protests, smaller rallies have been organised by professional groups such as teachers, students and medics.

On Saturday, around 50 medical workers held a protest outside a Minsk hospital, local news outlets reported. Dozens of them were detained.

In October, several state universities expelled students who organised sit-in protests on campus.

"We are citizens who have a conscience and who cannot be silent if lawlessness is happening in the country,” law student Tamara Babina, 20, told AFP at Sunday’s protest.

EU sanctions 

The European Union has slapped sanctions on Lukashenko, 66, and several of his allies, imposing a travel ban and asset freezes over vote-rigging and police violence.

Earlier protests in Minsk were met with a brutal crackdown with police using stun grenades and rubber bullets to disperse the gatherings.

Many of those detained reported brutal treatment including beatings and torture at the hands of security forces