Videos shared on social media showed young people in Minsk being struck by masked police officers, dragged away and loaded into vans as their peers look on.
The detentions followed major protests by the young in the Belarusian capital, with around 3,000 to 5,000 students marching to the city’s Independence Square on Tuesday, according to Human Rights watchdog Viasna 96.
The square is a central location in Minsk and has played host to several anti-government protests over the past few weeks.
Unrest in Belarus erupted last month after President Alexander Lukashenko’s contested victory in an August 9 election that independent observers have criticized for not being free and fair.
Viasna 96 described the police response to the student protests as heavy handed. At least 40 people were detained following the demonstrations.
There was no immediate response from the country’s government to the protests but Lukashenko dismissed the demonstrations while visiting a university in the town of Baranovichi Tuesday.
“This will all pass,” he said. Lukashenko mocked reports that millions had joined the anti-government rallies.
“Listen, if there was a million people [on the streets], we wouldn’t be speaking with you now,” he said.
CNN has contacted the Belarussian Ministry of Foreign Affairs for comment but has yet to hear back.
Tens of thousands of people have protested against Lukashenko’s re-election in recent weeks.
The 66-year-old is often described as Europe’s last dictator. His victory has been followed by a major clampdown on press freedom amid the groundswell of protest.
Nineteen Belarusian journalists were stripped by government authorities of their accreditation to work for the BBC and other foreign media outlets last week, while two Associated Press reporters were deported from the country.
Last week a video broadcast by local news outlet TUT.BY shows at least eight armored tanks moving in a convoy in Minsk.
Mikalai Anishchanka reported from Minsk and Zamira Rahim wrote from London.