MINSK, Belarus - Mysterious cell-phone text messages warning of bloodshed on election day spread in the Belarusian capital Saturday, a day before presidential voting that the opposition alleged was likely to be fraudulent.
The ominous messages underlined the tension surrounding the Sunday balloting in which President Alexander Lukashenko, characterized by the West as Europe's last dictator, seeks to extend his 12 years in power.
Authorities, meanwhile, warned of foreign plots to overthrow the government.
On Saturday afternoon, police armed with machine guns ordered the evacuation of a building housing offices of the opposition party Trud, said a party spokesman, Sergei Vaznyak.
Associated Press photographers outside the building saw several people put in a police car and driven away. A member of a European election observation mission accompanied them to monitor their treatment, mission spokeswoman Urdur Gunnarsdottir said.
Lukashenko is almost certain to be declared the winner of the race against three other candidates. But opposition figures are equally certain the vote count will be manipulated and have called on supporters to gather Sunday evening in the capital.
The government has banned rallies on election day, and the head of the KGB said this week that any protesters who take to the streets could be subject to charges of terrorism.
The text messages received by subscribers to the country's largest mobile phone operator Saturday morning said "provocateurs are planning bloodshed" Sunday evening at Oktyabrskaya Square, where protesters are expected to try to gather. "Watch out for your life and health."
The phone company, Velcom, refused to comment on who was sending the messages.
Belarusian authorities last week alleged that opposition supporters were planning to set off explosions at rallies. That in turn led to opposition speculation that authorities would set off blasts as an excuse to disperse demonstrators.
Lukashenko, in a televised address to the nation on Friday night, said: "I guarantee that an overthrow of the government in our country will not take place. ... Everything is being done to prevent even the smallest threat to the security of the people."
Authorities this week unleashed an array of allegations that the opposition, with Western support, was planning post-election disruptions or attempts to spread falsified vote results showing main opposition candidate Alexander Milinkevich as the winner.
The allegations included the KGB showing a videotaped statement by an unidentified man saying he had received terrorist training in Georgia on making bombs and using dead rodents to poison water supplies.
Georgia was the scene of the 2003 "Rose Revolution," where tens of thousands of protesters massed after disputed parliamentary elections and drove President Eduard Shevardnadze out of power. It was the first of a wave of protests in former Soviet states, which also helped bring opposition figures to power in Ukraine and Kyrgyzstan.
Nine Georgian lawmakers who were to take part in the Organization for Security and Cooperation in Europe's election observation mission were detained at Minsk's airport Thursday when trying to enter the country. They were to be sent back to Georgia Saturday evening, said Grigory Mobisevich, a duty officer for the border guards' service.
Three activists from Russia's liberal Yabloko party were detained Saturday in Gomel, a major Belarusian city, said party spokeswoman Yevgeniya Dilendorf.
The United States and European Union have issued repeated warnings to Belarusian authorities against cracking down on protests and have called on opposition supporters not to provoke violence.
"We appeal to all parties to show restraint. Obviously we are concerned about the lack of freedom and at the harassment of the opposition," European Commission President Jose Manuel Barroso said Saturday in Moscow.
Scores of opposition supporters have been detained. Alexander Kozulin, another opposition candidate, was beaten by government security agents this month when he tried to enter a conference chaired by Lukashenko.
The state-run newspapers and TV stations that dominate Belarus' media have given little coverage to Milinkevich and Kozulin. Authorities have seized hundreds of thousands of copies of independent newspapers.