Protesters gathered in central Minsk for the eighth consecutive Sunday rally against Belarusian President Alexander Lukashenko.
Police deployed water cannon and detained protesters from the crowd, with some attendees retaliating by attacking a police water cannon.
Videos of the protests show tens of thousands of people marching in the city, waving flags and chanting opposition slogans.
Anti-Lukashenko protests have rocked the country over the past two months, with the largest rallies in Minsk attracting up to 200,000 people.
During the first days after the election, police used tear gas, truncheons and rubber bullets to disperse crowds.
Several protesters died, many were injured and nearly 7,000 were detained.