Belarus President Alexander Lukashenko won a fourth term on Monday after a landslide election marred by a violent police crackdown on demonstrators and the arrest of opposition challengers.
On Sunday up to 10,000 people marched through the snow-bound capital Minsk chanting "Out!", "Long Live Belarus!" and other anti-Lukashenko slogans in one of the most significant challenges yet to his 16-year rule.
(An opposition supporter smashes the glass on a door of the Parliament building during a rally.)
Then riot police waded in, beating people with batons on Independence Square, a Reuters reporter at the scene said. Some protesters in the ex-Soviet republic threw stones and snowballs at police.
Several people were left sprawled on the ground, including an elderly woman who had been hit on the head. Others were bundled into police cars. The opposition reported at least three candidates detained.
The Interior Ministry accused Neklyayev's supporters of provoking the clash.
Early on Monday the state electoral commission said Lukashenko had won 79.7 percent with 100 percent of votes counted. It put voter turnout in sub-zero temperatures at more than 90 percent.
The opposition accused Lukashenko of rigging the vote.
The head of the European Parliament, Jerzy Buzek, said the incident involving Vladimir Neklyayev was unacceptable. "This cowardly attack on a defenceless candidate for President of Belarus is outrageous and disgraceful," he said in a statement.
An aide to nationalist candidate Grigory Kostusev said the 53-year-old had been stopped in his car and arrested.
(Presidential candidate Vladimir Neklyayev lies on a street after he was beaten during a rally in Minsk.)
In the main rally, some demonstrators broke the glass doors to the government building but were restrained by others in the crowd, a Reuters reporter said.
Veteran leader Lukashenko, 56, had earlier scoffed at the opposition's plans to protest against the conduct of the election. He predicted nobody would turn out.
During Lukashenko rule Belarus's command economy has been propped up by energy subsidies from chief ally Russia. The country serves as a buffer between Russia and NATO and a transit route for Russian gas heading to Europe.
The European Union has dangled the prospect of financial aid if Sunday's vote is deemed fair. It will take its cue from monitors from the Organisation for Security and Cooperation in Europe (OSCE), who report back on Monday.
The OSCE had said on Sunday that the election already appeared better than in 2006.