EU leaders reportedly agreed to restrictions beyond the current six visa bans in place against

Belarus officials, but that the exact nature of the measures had not been decided.

"The European Council has decided to take restrictive measures against those responsible for the violations of international electoral standards, including President Lukashenko," Austrian Foreign Minister Ursula Plassnik, who currently holds the EU presidency, told reporters.

She added that the freezing of assets was a possibility, but that economic sanctions were not discussed.

EU leaders condemn arrests of opposition supporters

Earlier in the day, Plassnik had called on Lukashenko's government to free people that had been arrested as an opposition camp in Minsk had been raided by police Friday morning. Some 300-400 protestors were herded or carried into green trucks with barred windows. There was no violence or resistance.

"We urge the Belarus authorities to respect the freedom of assembly and to release the prisoners," Plassnik said.

EU leaders arriving for the second day of the Brussels summit widely condemned the crackdown and said that Belarus's giant neighbour and ally, Russia, had to be engaged.

"We need to be more firm ... and demonstrate that we are united inside the European Union about how we look at the relations with Belarus but also with Russia," said Swedish Prime Minister Goran Persson. "We have to give all possible support to the democratic forces inside the country."

Luxembourg's Foreign Minister Jean Asselborn said: "I think what happened last night is really very, very negative. Young people on the street, they have the right to protest, to make known their opinion about this regime."

"We have to be tough, but we also have to speak with our Russian friends, that is the most important, I think," he told reporters.

The opposition protests began after Lukashenko was swept back into power in Sunday's presidential election -- a vote widely accepted as unfair and slammed by the EU this week.

In Washington, the US State Department said it was "disturbed by the breakup of the demonstration and the detention of protestors."

Polish diplomat detained

The dramatic raid came on the fourth consecutive night that opposition activists -- mostly students -- peacefully occupied their tent camp on the vast, icy central square.

They had stood day and night in a protective human shield around their cluster of 35 tents, chanting slogans such as "Freedom!" and waving banners and flags, including that of the European Union.

Among those detained in the police raid was a stepson of Milinkevich. Also detained was a Polish diplomat and former ambassador to Minsk, Mariusz Maszkewicz, the Polish consulate and witnesses said.

"They are not giving any information," Poland's consul, Krzysztof Swiderek, told AFP outside the prison where the demonstrators were being held. "They won't let us see him. That's a violation of the Geneva Convention."

The raid leaves Belarus' opposition in crisis. Already, more than 250 people had been arrested since Sunday, according to human rights organizations.

State television has been running hours of reports daily aimed at discrediting Milinkevich and the demonstrators as Western agents and social deviants.

Milinkevich defiant

But Milinkevich, who according to official results won only 6.1 percent of Sunday's vote, compared to 83 percent for Lukashenko, remained defiant.

"We will continue with what we planned for (Saturday)," Milinkevich told reporters. "These authorities can only speak one language, that of repression. They showed that again. I had been expecting this each night."

It was not immediately clear whether the authorities would now allow the demonstration that Milinkevich promises on Saturday -- or whether the opposition leader himself could face charges of organizing illegal protests.

The opposition has received political backing from the European Union and United States, where the White House considers Lukashenko a "dictator." On Wednesday, a group of European ambassadors in Minsk even went to October Square to lend moral support to the peaceful protest.