Hundreds of students marched across the capital, chanting “Go away" to demand that President Alexander Lukashenko step down. They were blocked by police, who rounded up some and forced others to disperse.
Later in the day, hundreds of women, some holding white-and-red umbrellas in the colors of the opposition flag, staged their regular weekend march across the capital, Minsk. “You sang your song, it's time to get off the stage!” one placard read.
The Viasna human rights center said more than 30 demonstrators were detained.
Earlier this week, the top opposition challenger, Sviatlana Tsikhanouskaya, who moved to Lithuania after the election under pressure from Belarusian authorities, put forward an ultimatum to Lukashenko: announce his resignation by Oct. 25 or face a nationwide strike.
Tsikhanouskaya hailed the participants of Saturday's rallies as a “big and bright force.”
Lukashenko, who has run the ex-Soviet nation with an iron fist since 1994, has accused the West of fueling the protests and relied on support from his main sponsor and ally, Russia, to dig in.
Belarusian authorities tried to squelch the protests with massive violence in the first days after the vote, dispersing peaceful demonstrators with stun grenades and rubber bullets, detaining thousands and beating hundreds. The crackdown drew international outrage and helped swell the number of protesters, peaking each Sunday with over 100,000 on the streets.
Another such protest is scheduled for Sunday.
Since then, the government has scaled down the violence but maintained the pressure, regularly detaining scores of protesters and prosecuting top activists. Prominent members of the opposition’s Coordination Council, formed to push for a transition of power, have been arrested or forced to leave the country.
Authorities also have made methodical efforts to stifle independent media, regularly rounding up reporters covering protests and threatening them with jail terms for taking part. Several journalists were detained on Saturday.