TALLINN, Estonia (AP) — An opposition politician who ran against authoritarian Belarusian President Alexander Lukashenko in the controversial 2020 presidential election pleaded guilty Wednesday at the start of his trial on charges of public order breaches.

Andrey Dzmitryeu, 41, was detained Jan. 11 and charged with “organizing and preparing actions grossly violating public order.” The activist, who heads the Tell the Truth movement, faces up to four years in prison.

According to the Viasna human rights center, Dzmitryeu admitted participating in opposition rallies three times and blocking the streets in the Belarusian capital, Minsk.

At the hearing at Minsk’s Moscow Court, Dzmitryeu was held in an iron cage-like enclosure and looked noticeably tired and thin.

Following his arrest, Dzmitryeu was held at the notorious Okrestsina Detention Center, where human rights activists say political prisoners have been tortured.

Belarus was shaken by huge anti-government protests after the disputed August 2020 re-election of Lukashenko, which the opposition and the West denounced as having been rigged. Belarusian authorities responded to the demonstrations with a major crackdown that saw more than 35,000 people arrested, thousands beaten by police and dozens of media outlets and nongovernmental organizations shut.

Running against Lukashenko, Dzmitryeu finished fourth in the election with 1.2% of the vote, according to the official results. During the election campaign, Dzmitryeu spoke in support of Sergei Tikhanovsky, Viktar Babaryka and Valery Tsepkalo, who were barred from running in the election.