Thousands of women marched through the capital of Belarus on Saturday, calling for the resignation of Alexander Lukashenko.
University students also demonstrated against the detention of classmates during the wave of protests that have gripped the country for the past four weeks.
For the first time in the demonstrations, supporters of LGBT rights appeared with rainbow flags in the women's march in Minsk, an indication that opponents of President Lukashenko are becoming bolder.
Although homosexuality was decriminalized in Belarus in 1994, stigmatization of it is strong.
Authorities haven't allowed any LGBT organisation legal registry; same-sex marriage is prohibited.
About 5,000 women took part in the march, according to the human rights organisation Viasna.
Police followed the march, but no detentions were reported.
Marches and demonstrations by women have become a frequent feature of the protests.
They broke out on August 9 after the election in which Lukashenko, who has been in power since 1994, was officially tallied with an 80 percent landslide victory.
Protests took place after some previous elections that Lukashenko won with lopsided margins, but this year's have been by far the largest and longest-lasting. Sunday protests have been especially large, bringing crowds estimated at well over 100,000 people.
Earlier in the day, hundreds of students formed human chains to demonstrate against the detention of students at the State Linguistics University. Viasna said about 20 of the students were detained on Saturday.
Lukashenko's opponents have formed a Coordination Council to drive the protests and push for a transition of power.
On Saturday, one of its most prominent members, Olga Kovalkova, surfaced in Poland after being jailed in Belarus for organising protests.
She told reporters that police came to her in jail during the night and said she could either leave the country or face a long term in prison. Masked police then drove her to the border, she said.