Thousands of market traders massed in the Belarus capital to demand President Alexander Lukashenko's government resign over a new tax law they say could force many of them out of business.
Demonstrations in ex-Soviet Belarus are rare, particularly when the demands are overtly political, and usually end in police action to disperse them.
Protests by traders making economic demands are more frequent and usually avoid violence.
Anatoly Shumchenko, an organiser of Tuesday's rally, said 80,000 traders and businessmen were prepared to launch a strike throughout the country of 10 million to resist a law requiring individual entrepreneurs to start paying value added tax.
Up to 5,000 people chanted "Resignation!" and waved banners "Down with the government" and "Down with VAT" in Oktyabrskaya square in the heart of Minsk.
"Our aim today is not a revolution. We just want to work in a normal fashion," Shumchenko told the crowd.
Businessmen had previously been subject to a tax pegged at about $150 a month. They say the new rules introduced by the government in mid-February will increase their tax burden and plunge many firms into the red.
"Our aim today is not a revolution. We just want to work in a normal fashion"
The economy in Belarus is run along Soviet-era lines with the government controlling most prices and ordering companies what to produce. Private initiative is stymied by red tape and strong government interference.
Lukashenko, in power since 1994, is accused by Belarus's small opposition and by the West of stifling media freedoms and cracking down on his political rivals.
Slow progress in economic reforms and falling living standards have dented his popularity ratings, though a referendum last year approved a constitutional amendment allowing him to run for a new term in 2006.