Border officials in Belarus say Maria Kolesnikova, an opposition figure who had been reported missing, was detained while trying to enter Ukraine.
Anton Bychkovsky, a spokesman for the State Border Committee, said Kolesnikova had been detained in the early hours of Tuesday while trying to cross into Ukraine with two other opposition figures, who made it through.
He said Kolesnikova was being held and an investigation was underway to legally assess the situation.
The Ukrainian Embassy in Minsk confirmed to AFP that Rodnenkov and Kravtsov had entered Ukraine.
Reports said on Monday that Kolesnikova and her two fellows Anton Rodnenkov and Ivan Kravtsov had disappeared.
Some media reports had said earlier that unidentified people had abducted Kolesnikova near the National Art Museum in the capital, Minsk, on Monday.
“We agreed that she would go to the post office to fetch a letter from the central police department… Eyewitnesses say they got her into a minivan with the word ‘communications’ written on it and took her to an unknown location,” Maxim Znak, another opposition figure, said, referring to a police notice that she was sent on an administrative offense she committed by attending an unauthorized rally last month.
A missing person report had been filed with the police.
Two other opposition figures, Ivan Kravtsov and Anton Rodnenkov, have also gone missing.
EU threatens sanctions
In reaction to Kolesnikova’s disappearance, European nations blamed the incident on the Belarusian government, threatening sanctions.
The European Union (EU)’s High Representative for Foreign Policy Josep Borrell accused the Belarusian authorities of “unabating arbitrary and unexplained arrests and detentions on political grounds.”
Brussels urged President Alexander Lukashenko’s government to ensure the “immediate release” of all those arrested, while threatening to impose sanctions against his administration.
“The EU will impose sanctions on individuals responsible for violence, repression and falsification of election results,” he said in a statement on Monday.
Belarus has been rocked by protests since the August 9 presidential election, which Lukashenko won. The Belarusian opposition and Western countries quickly alleged voter fraud, and mass protests followed. The Belarusian government has rejected allegations of vote rigging.
German Foreign Minister Heiko Maas said also on Monday that his country demanded “clarity about the whereabouts and the release of all political prisoners in Belarus.”
In comments tweeted by the Foreign Ministry, Maas warned that, “If Mr Lukashenko does not change his course, we in the EU will react.”
British Foreign Secretary Dominic Raab also said that Minsk “must make her (Kolesnikova’s) safe return their highest priority.”