Belarusian security forces detained more than 100 protesters on Sunday at rallies in Minsk the opposition had billed as "the march of neighbours", a rights group reported and videos on local social media showed.
Thousands of protesters met at various locations, mostly in remote residential areas of the capital, and marched through the streets demanding the resignation of President Alexander Lukashenko, a witness said.
Police did not immediately answer calls seeking comment.
Belarus has been in crisis since a presidential election in August that the opposition says was rigged, something Lukashenko, who has been in power for 26 years, denies.
"Get out, you and your OMON!" chanted some of the protesters, using a short name for anti-riot police who have been accused of brutality against demonstrators.
Some cars honked when they passed a crowd of protesters in the north-western part of Minsk and slowed down to block traffic at a narrow street to prevent a police bus from reaching demonstrators, the witness told Reuters.
Tens of thousands of protesters take to the streets in Belarus weekly to demand Lukashenko quits.
"We shouldn't stop it, because if we stop, we will get back to 1937 and I don't want this to happen," said one of protesters Andrei, 32, referring to the worst year of mass repression under Soviet ruler Joseph Stalin.
As many as 60 local rallies took place in Minsk on Sunday, a Belarusian independent news outlet, Nasha Niva, calculated.
The Belarusian Viasna-96 (Spring-96) rights group said 123 people had been detained as of Sunday afternoon. Videos posted on local social media showed uniformed men, many in helmets, grabbing people in civilian clothes and beating at least one of them.
