Many of those arrested have been sentenced to up to 15 days in prison.
Rights activists say 20 inmates at a detention center east of Minsk have gone on hunger strike.
A lawyer for Alyaksandr Kazulin, an opposition leader jailed during the March 25 protest in Minsk, said his client had been mistreated. Igor Rynkevich said police kicked Kazulin frequently and bound his wrists with handcuffs at maximum tightness.
Former Czech president Vaclav Havel today called on Belarusian authorities to released those detained.
(compiled from agency reports)
THE AUTHORITIES GET TOUGH: RFE/RL's Belarus Service filed these images from the police action against the March 25 demonstration in Minsk. Photographs by Maks Kapran.
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