Saturday's protest in the Belarusian capital comes as Belarusian President Alexander Lukashenko is holding talks with Russian President Vladimir Putin in Sochi on Russia's Black Sea coast.
The two presidents are discussing economic agreements intended to bring the two ex-Soviet neighbors and allies even closer. Lukashenko, who has ruled Belarus with an iron fist for more than a quarter-century, relies on cheap Russian energy and loans to maintain a Soviet-style economy.
The Kremlin has cranked up pressure on Belarus, raising energy prices and cutting subsidies, but Lukashenko vowed not to surrender Belarus' post-Soviet independence.
Some in Belarus fear that the agreements could pave the way for afull merger — concerns fueled by Russia's 2014 annexation of Ukraine's Crimea.