Belarusian authorities drove prominent opposition leader Maria Kolesnikova to the border with Ukraine on Tuesday, a day after she was snatched from the street in Minsk, but she tore up her passport so they could not force her to cross, two of her allies said.

The fate of Kolesnikova, a key figure during four weeks of mass protests against President Alexander Lukashenko, had been a mystery since supporters said masked men had whisked her away in a van on Monday. Belarusian police were quoted as saying they had not detained her.