The group says at least two of the journalists needed hospitalization. Some of the journalists were temporarily detained by police.
U.S. State Department spokesman Adam Ereli said on March 3 that Washington condemned the arrest of Kazulin.
These actions "reinforce our fears that a free election process will be compromised."
Washington called on the Belarusian authorities to release the journalists and "to conduct an impartial investigation into the beating of the leader of the opposition and to hold the perpetrators accountable."
Belarusians will vote in a presidential election on March 19.
(AFP)