Police arrested more than 1,000 people protesting in Belarus against the government and police brutality.
Human rights groups said that tens of thousands of people took to the streets in the capital Minsk on Sunday, prompting government forces to be deployed.
The fresh demonstrations came just days after the death of an opposition activist, which has sparked a nationwide outcry. The activist, 31-year-old Roman Bondarenko, was arrested and detained before his death late last week. Reports emerged alleging that he may have been beaten to death by security forces.
According to the human rights group Viasna, thousands of people have so far been arrested in the weekly protests organized by the government's opposition.
Protests began in August after longtime leader Alexander Lukashenko proclaimed that he won the presidential elections. The opposition alleged that the elections were rigged and called for Lukashenko's resignation. Lukashenko has ruled the country for the past 26 years.
The European Union condemned the killing of the protester and the continued arrests of political opposition members. The bloc described Bondarenko's death as "outrageous" and "shameful." Both Lukashenko and his son have been added to the EU's sanction blacklist of government officials.
Since Lukashenko proclaimed his victory, more than 100,000 people have protested on the street of Minsk. While most protests over the past weeks have been peaceful, recent demonstrations have turned violent.
Lukashenko has continued to ignore repeated requests for a new election and slammed the opposition for continuing to organize demonstrations. The international community has also called on the longtime leader to put an end to police brutality and to release detained political prisoners.
The Organization for Security and Cooperation in Europe said it had received verified reports of human rights abuses since the demonstrations began. It said that "massive and systematic" abuses have been conducted and proven "beyond doubt." The group is requesting that the prior elections be voided as "irregularities at all stages of the process" was apparent.