Trials of protesters in Belarus who took part in unsanctioned rallies held in Minsk and other Belarusian cities began in the capital on Monday.
Some 380 people were arrested in Belarus during Sunday's rallies, the Vesna human rights center said on Monday. "Over 200 people were arrested in Minsk," Vesna said. "About 180 people were arrested in other Belarusian cities."
The activists said that several journalists were also among those arrested.
At least 140 people will be tried in Minsk alone, Vesna said. The protesters may face up to 15 days of imprisonment and fines.
A new wave of protests in Minsk and other cities on Sunday saw police use tear gas to break up a protest in Minsk in which demonstrators clapped over an Independence Day speech by President Alexander Lukashenko.
Lukashenko, dressed in a military uniform, told the crowd that a plot was underway to bring about a "color revolution" similar to those in other former Soviet states, including neighboring Ukraine.
The unusual act of dissent during the speech was part of the new wave of protests in the authoritarian former Soviet republic in which demonstrators gather and simply clap.
The protests are organized via the internet and the Belarusian authorities closed down a number of social media sites prior to Lukashenko's speech.
Belarus has seen unprecedented economic and political turmoil in recent months, as increasingly frequent protests against the 17-year reign of the authoritarian Lukashenko have combined with a 36% devaluation of the national currency.