A rally in Belarus marking the 20th anniversary of the Chernobyl nuclear disaster Wednesday turned into an anti-government protest.
At least 7,000 demonstrators waved flags and shouted chants of "Freedom" outside the Academy of Sciences in central Minsk.
Opposition leader Alexander Milinkevich ignored authorities' orders not to go to the rally.
He told the crowd that the people will not wait another five years to drive President Alexander Lukashenko from power. He said peaceful protests must continue.
Many in the crowd also accused the Lukashenko government of moving too slowly to clean up areas contaminated by the 1986 Chernobyl blast.
President Lukashenko toured the affected areas Wednesday, promising more government help.
Mr. Lukashenko was elected to a third term last month by a landslide in a vote the West called a fraud.
The United States calls Mr. Lukashenko Europe's last dictator because of his suppression of human rights and free speech.
Some information for this report was provided by AFP, AP and Reuters.