Video posted online showed the security forces in Moscow sweeping up protesters and suspected opposition members.
Protesters in Moscow braved a heavy ice-storm that paralyzed parts of the city to gather in a downtown square on Tuesday evening in protest against what opposition leaders say is a concerted crackdown on dissent by security forces.
Despite an effort to stifle documentation of the crackdown in Hama, video that appeared to show tanks in the city's central Aasi Square was posted online by an opposition activist early on Wednesday.
Moscow police on Saturday briefly detained several opposition leaders as well as a dozen other activists while they were protesting against the intensifying crackdown on Russian opposition.
Video posted online shows a violent crackdown on opposition protesters in Belarus on Sunday.