Minsk police have forcibly dispersed an unsanctioned demonstration by some 40 opposition activists on Kastrychnitskaya Square, RFE/RL's Belarus Service reports.
Tens of protesters were detained.
The rally was held to mark the 10th anniversary of the disappearance of politician Viktar Hanchar and businessman Anatol Krasovsky, whose whereabouts are still unknown.
Their friends and relatives believe they were abducted by Belarusian secret services.
In 2003, the Minsk Prosecutor-General's Office ended the investigation into their disappearances.