(CNN)Five weeks have passed since Belarus learned the results of its presidential election, in which the country's Central Election Commission announced that President Alexander Lukashenko, often described as Europe's last dictator, had won with 80.23% of the vote.
In the weeks that have followed, the country has seen mass protests from citizens who believe the vote was rigged, violent police crackdowns on those protestors and, possibly most disturbingly, three high-profile opposition figures -- all of whom are women -- have disappeared from public view or fled Belarus.
Belarusian state media said on Tuesday that Maria Kolesnikova, a key opposition figure, had been detained on the Belarusian side of the border between Ukraine and Belarus. The statement was made by Belarusian Border Control, and aired on state TV.
"The disappearance of the candidates demonstrates beyond all doubt the brutality of this regime and how important it is that the international community doesn't lose interest in the appalling events that have unfolded since the election," Tom Tugendhat, chairman of the UK's Foreign Affairs Select Committee, told CNN.
Kolesnikova joined forces with fellow opposition candidates Svetlana Tikhanovskaya and Veronika Tsepkalo to take on Lukashenko in the election after several opposition candidates were either barred from running or jailed.
Tikhanovskaya and Tsepkalo left Belarus in the immediate aftermath of the election, while Kolesnikova stayed and spoke out against the result. She told CNN in an interview on August 13 that Lukashenko "has to accept that the Belarusian people don't like him and don't like for him to stay the President of Belarus."
Maria Kolesnikova
Kolesnikova disappeared in central Minsk on Monday. Two of her colleagues from the Coordination Council, the main Belarusian opposition group also disappeared shortly after.
Her colleagues passed through the Alexandrovka checkpoint into Ukraine at 4 a.m., according to Belarusian Border Control. Kolesnikova did not.
Ukrainian State Border Guard Service press officer Oleg Bokyo said Kolesnikova "did not arrive at the checkpoint of Ukraine for border control."
Speaking to CNN's Christiane Amanpour from her exile in Ukraine on Monday, Tikhanovskaya said: "At the moment, members of the Coordinated Council I created are chased, kidnapped and harassed. And it's worrying me a lot, because at the moment we still don't know where Maria Kolesnikova is."
Svetlana Tikhanovskaya
Tikhanovskaya, the main opposition candidate in August's disputed presidential election, left the country days later -- after security forces mounted a sweeping crackdown on protests over the result.
Tikhanovskaya, who stood in for her husband as an opposition candidate after he was jailed, is now in neighboring Lithuania with her children, according to her campaign.
She had publicly questioned the result of the election, demanding a recount after the Central Election Commission announced that she had only won 9.9% of the vote.
"We do not recognize the election results," she said. "We have seen real protocols. We urge those who believe that their voice was stolen not to remain silent."
Veronika Tsepkalo
Tsepkalo, who served as an adviser to Tikhanovskaya, meanwhile, fled Belarus for Moscow for safety reasons before the election took place, her campaign told CNN.
Tsepkalo's husband Valery Tsepkalo, the former Belarusian ambassador to the US, was not allowed to register as a candidate and had previously gone to Russia with their children, fearing for their safety after receiving threats of arrest.
The family is now in exile in Poland. Tsepkalo told Reuters on August 19 that the "only legitimate President is Svetlana Tikhanovskaya ... our main aim is just to make Lukashenko go," adding that she would like to go back to Belarus but understands the chances of her going to jail are "very, very high."
Sebastian Shukla in London, Mikalai Anishchanka in Minsk, Denis Lapin in eastern Ukraine and Mary Ilyushina in Moscow contributed to this article.