MINSK, Belarus (CNN) -- The European Union has condemned violence used by Belarus authorities to quell demonstrations and called for the "immediate release" of an arrested opposition leader.
Black-clad riot police clubbed demonstrators and detained leader Alexander Kozulin on Saturday as they defied a show of force by President Alexander Lukashenko, whose recent re-election has drawn international condemnation.
Austria, which holds the rotating EU presidency, said in a statement Sunday that it was "appalled by the violence used against demonstrators by the Belarusian authorities."
It also demanded the immediate release of Kozulin and other opposition members, and it called for international solidarity.
Austria "urges the international partners of the EU, and in particular Belarus' other neighbors, to follow the same approach towards Belarus," the statement said.
Kozulin was among demonstrators detained by riot police Saturday when protesters tried to heed his call to march to a Minsk jail where other demonstrators were being held. (Full story)
Police also detained the press secretary of Alexander Milinkevich, the top opposition figure, aides said.
Kozulin's daughter Julia told CNN her father was charged with hooliganism and taken to a jail about 45 kilometers (28 miles) from the capital Minsk.
Kozulin's wife said her husband was in good condition. Reports earlier said he may have been beaten, but Irina Kozulin told The Associated Press "the condition of his health is OK. The rescue squad wasn't called for him."
Kozulin was one of three candidates who ran March 19 against Lukashenko, who won in a landslide for a third term.
Opposition leaders say the vote was fraudulent, and the United States and the EU say the government blocked a truly democratic vote through use of state power and detentions.
The election result set off several days of rare protests, which has seen violent clashes between police and demonstrators involving beatings, tear gas and percussion grenades.
The human rights group Vasnya said more than 100 people were detained Saturday, AP reported.