Two human rights activists were detained by police in the western Belarusian town of Berastse on May 7, RFE/RL's Belarus Service reports.
Police arrested Roman Kislyak and Andrey Sharenda as they distributed texts of the "International Convention for the Protection of All Persons from Enforced Disappearance" not far from the local prosecutor's office in Berastse.
The action by the rights defenders was to mark the 11th anniversary of the disappearance of former Belarusian Interior Minister Yury Zaharanka.
Several prominent individuals disappeared in Belarus in 1999 and 2000, including former Deputy Parliament Speaker Viktar Hanchar, businessman Anatol Krasousky, journalist Dzmitry Zavadzsky, and Zaharanka.
All of them are presumed dead. Their relatives believe the Belarusian secret services are behind the abductions and possible killings.
Sharenda has been arrested and jailed in recent years for such things as taking part in unsanctioned gatherings and putting the opposition's national flag on a university building.