By Andrei Makhovsky and Richard Balmforth
MINSK (Reuters) - At least seven election candidates and hundreds of opposition demonstrators were being held on Monday after police cracked down on a protest against the re-election of Belarus President Alexander Lukashenko.
Lukashenko, who immediately came under fire from international election monitors for flawed vote counting and police heavy-handedness, accused demonstrators of banditry.
"There will be no revolution or criminality in Belarus," he said, adding that security forces had stood firm against "barbarism and destruction" by militants.
Lukashenko also described criticism by an observer mission from the Organization for Security and Cooperation in Europe, the democracy and human rights watchdog, as amoral.
After a night of mayhem in central Minsk involving riot police and thousands of demonstrators, the central election commission declared in the early hours that Lukashenko, in power since 1994, had secured nearly 80 percent of the vote.
Opposition parties say supporters of the 56-year-old former Soviet state farm director had rigged his re-election at the vote counting stages, much as they had in 2006.
In a verdict that could have implications for Belarus's future relations with the West and the European Union, the OSCE mission described the election vote count as flawed and said police action against demonstrators had been heavy-handed.
"This election failed to give Belarus the new start it needed," Tony Lloyd, head of the short-term OSCE observer mission told a news conference.[nLDE6BJ101]
A positive judgment by the OSCE had been seen as key to possible EU financial aid for the ex-Soviet republic's economy.
A combative Lukashenko said the OSCE had no right to look at events outside the election itself. "We did everything they had asked of us," he told a news conference just an hour after the OSCE had delivered its verdict.
EU foreign affairs chief Catherine Ashton criticized the violence and called for authorities to release those arrested. Poland and Germany also expressed concern over the vote.
However, a parallel observer mission from the Russian-led Commonwealth of Independent States gave the election a clean bill of health.
In Moscow, Russian President Dmitry Medvedev said the election was an "internal matter" for Belarus. He did not comment on the police crackdown.
In a Belarus Interior Ministry statement, police justified their action, saying protesters had tried to storm the main government building.
On Sunday night up to 10,000 people marched through the snow-bound capital chanting "Out!", "Long Live Belarus!" and other anti-Lukashenko slogans in one of the most significant challenges to his iron-fisted, 16-year rule.
Then riot police waded in, beating people with batons on Independence Square. Some protesters in the ex-Soviet republic threw stones and snowballs at police.
THREAT OF JAIL
Several people were left sprawled on the ground. Others were bundled into police cars.
One opposition leader, Vladimir Neklyayev, was beaten by police who fired into the air to disperse a column of supporters trying to join the main rally.
His wife, Olga, said he was later taken by police from his hospital bed, where he had been recovering from head injuries. She had tried in vain to find out from the authorities where her husband was. "They either answered that they didn't know, or wouldn't answer at all," she told the OSCE news conference.
Apart from Neklyayev, 56-year-old Andrei Sannikov and at least five other candidates out of the nine who ran against Lukashenko were being held, the pro-rights Vyasna (Spring) website and opposition aides said.
The state prosecutor's office said some protest leaders could face up to 15 years in jail for stirring mass unrest.
The Interior Ministry statement, focusing on an attempt by some demonstrators to break down the door of a government building, said: "A peaceful meeting grew into an attempt to seize the building of the Council of Ministers by storm."
Many demonstrators had been drunk and the police had later recovered wooden sticks, metal bars and empty bottles, it said.
The EU is weighing how far to engage with the country of 10 million on its eastern flank, amid tension between Lukashenko and chief benefactor Russia.
Lukashenko crushed dissent in the early years of his rule, jailing opponents and muzzling the media. The administration of former U.S. President George Bush called him Europe's "last dictator".
Under Lukashenko, Belarus's command economy has been propped up by energy subsidies from Russia. The country serves as a buffer between Russia and NATO and a transit route for Russian gas heading to Europe.
But relations with Moscow have been on the rocks in recent years and the EU has been dangling the prospect of financial aid if Sunday's vote was deemed fair. (Writing by Richard Balmforth and Matt Robinson; additional reporting by Lidia Kelly, Gabriela Baczynska in Warsaw, Luke Baker in Brussels, Brian Rohan in Berlin and Denis Dyomkin in Moscow; editing by David Stamp)