One man has died in protests in Belarus as demonstrators clashed with police for a second night after a disputed election handed a sixth term to strongman Alexander Lukashenko.

Thousands took to the streets of the capital Minsk Monday night, saying Lukashenko had stolen the election from his surprise challenger, political novice Svetlana Tikhanovskaya.

Tikhanovskaya stepped into the race at great personal risk after the detention of her husband, who had hoped to stand himself Tikhanovskaya stepped into the race at great personal risk after the detention of her husband, who had hoped to stand himself Photo: AFP / Sergei GAPON

Police used rubber bullets, stun grenades and tear gas but demonstrators fought back with stones and fireworks and built makeshift barricades, AFP reporters, protesters and witnesses said, in chaotic scenes of defiance in the authoritarian former Soviet republic.

"Too many people are against Lukashenko," Pavel, a 34-year-old protester, told AFP.

Lukashenko, shown here at a military parade in May, has warned of outside threats and raised the spectre of violent mobs Lukashenko, shown here at a military parade in May, has warned of outside threats and raised the spectre of violent mobs Photo: POOL / Sergei GAPON

"Our goal is to depose Lukashenko. He is not worthy of being president."

At one flashpoint in Minsk, protesters -- mostly men but also several women -- used sacks, buckets and metal barriers to build barricades, an AFP photographer said.

The whereabouts of Tikhanovskaya -- who has claimed victory in Sunday's poll and called for Lukashenko to step down -- were unknown as of late Monday.

Lukashenko has maintained close ties with Moscow. He is seen here with Vladimir Putin in Russia on June 30 Lukashenko has maintained close ties with Moscow. He is seen here with Vladimir Putin in Russia on June 30 Photo: SPUTNIK / Mikhail KLIMENTYEV

A man died when an explosive device went off in his hand Monday night, police said, confirming the first casualty of the post-election protests.

"One of the protesters tried to throw an unidentified explosive device at members of law enforcement. It exploded in his hand," the interior ministry said, adding that he died of his injuries.

A woman in Minsk holds up a placard reading 'Freedom to Sergei Tikhanovsky' at a campaign rally for the jailed blogger's wife, presidential candidate Svetlana Tikhanovskaya, last month A woman in Minsk holds up a placard reading 'Freedom to Sergei Tikhanovsky' at a campaign rally for the jailed blogger's wife, presidential candidate Svetlana Tikhanovskaya, last month Photo: AFP / Sergei GAPON

A police spokeswoman could not immediately say how many people had been injured in Monday's clashes.

Tikhanovskaya had said earlier she would not take part in the demonstrations to avoid "provocations."

"The authorities should think about how to peacefully hand over power to us," she told reporters.

Political observers say there is little doubt that Lukashenko, who is seeking a sixth term, would rig Sunday's vot Political observers say there is little doubt that Lukashenko, who is seeking a sixth term, would rig Sunday's vot Photo: AFP / Sergei GAPON

The 37-year-old mother of two decided to run for president after the authorities jailed her husband, popular blogger Sergei Tikhanovsky, and barred him from contesting.

Her campaign galvanised the opposition, presenting the most serious challenge to former collective farm director Lukashenko, who has ruled Belarus since 1994, brooking no dissent and earning the nickname of "Europe's last dictator".

Polling stations open in Belarus as voters cast ballots in presidential elections with President Alexander Lukashenko running for a sixth term against a strong opposition candidate, Svetlana Tikhanovskaya. Polling stations open in Belarus as voters cast ballots in presidential elections with President Alexander Lukashenko running for a sixth term against a strong opposition candidate, Svetlana Tikhanovskaya. Photo: AFPTV / Alexander GREBENKIN

Tikhanovskaya's whereabouts were not known to her campaign staff on Monday night, her spokeswoman Anna Krasulina told AFP.

On Monday Tikhanovskaya went to lodge a complaint with the Central Election Commission where she spent three hours, Krasulina told AFP.

After leaving the commission headquarters she had gone incommunicado, Krasulina added, without providing further details.

Tikhanovskaya has urged her supporters to wear white bracelets Tikhanovskaya has urged her supporters to wear white bracelets Photo: AFP / Sergei GAPON

The foreign minister of EU member Lithuania, another ex-Soviet republic, said he could not reach Tikhanovskaya as of late Monday.

"I tried to reach her for several hours but her whereabouts are unknown since she went to the election commission to file a protest over the vote count," Linas Linkevicius told AFP.

"It raises concern about her safety," Linkevicius said.

Earlier Monday, election officials confirmed Lukashenko's re-election for a sixth term, saying he had won more than 80 percent of the vote, with Tikhanovskaya coming second with 10 percent.

The White House said Monday it was "deeply concerned", adding that "intimidation of opposition candidates and the detention of peaceful protesters" were among numerous factors that marred the election and its aftermath.

European governments also questioned the results, with Germany voicing "strong doubts" about the conduct of the vote and France urging restraint.

But Russian President Vladimir Putin congratulated Lukashenko, a longtime ally, as did Chinese leader Xi Jinping.

Lukashenko was defiant, vowing he would not allow Belarus to be "torn apart."

"We recorded calls from abroad. There were calls from Poland, Britain and the Czech Republic, they were directing our -- forgive me -- sheep," Lukashenko said.

Thousands took to the streets in cities across Belarus on Sunday night to denounce the vote, sparking clashes with members of law enforcement.

Police said they detained some 3,000 people, around 1,000 of them in Minsk, after those clashes.

Images released by pro-opposition media showed police firing stun grenades and rubber bullets into the crowds and a police van ramming into the demonstration and running down a protester.

Young protesters were seen covered in blood, lying immobile on the ground or being dragged away by police.

The Belarusian Investigative Committee said it had opened 21 criminal probes into "mass unrest" and using violence against police and detained more than 80 people.

"I am ashamed of what interior ministry forces did, I served in these forces," Sergei, a 45-year-old sheet metal worker, told AFP.