A human rights group in Belarus said Sunday that more than 30 people have been detained amid demonstrations against authoritarian President Alexander Lukashenko, who is running for another term.

Lukashenko, who has suppressed opposition and independent news media during quarter-century in power, is seeking a new term in an election scheduled for Aug. 9.

Nikolai Statkevich, one of Belarus’ most prominent opposition figures, was detained while heading for a protest in Minsk. Statkevich served six years in prison for involvement in protests after the 2010 election.

On Friday, popular opposition blogger Sergei Tikhanovsky was detained during a rally in Grodno, the country’s fourth-largest city.

The human rights group Vesna said Sunday that more than 30 people in all had been detained in recent days.