They say they simply wanted to hold a peaceful demonstration on Independence Day.
Instead Belarus security forces moved quickly to quash any sign of protest against the 17-year rule of President Alexander Lukashenko.
Some 100 people arrested have been convicted of what authorities claim was hooliganism, and sentenced to between nine and 15 days in prison.
One man holding a baby, and surrounded by police, said: “I don’t want this future for my child, what the powers-that-be propose.”
A woman yelled at a policeman: “I helped to build this country and you tell me where I have the right to be?”
The protesters are part of a growing anti-government movement, which calls on people to protest against Lukashenko by clapping in unison.