Jailed Belarusian protest leader Maria Kolesnikova was in a stable but serious condition in the intensive care ward of a hospital on Tuesday after undergoing surgery, her sister and opposition politician Viktor Babariko's Telegram account said.
Reuters was unable to verify her whereabouts or condition. The jailed Babariko's Telegram channel said Kolesnikova, an outspoken critic of Belarusian President Alexander Lukashenko, had been taken to a hospital in the southeastern city of Gomel on Monday.
In an interview with Russian independent TV station Dozhd (TV Rain), which broadcasts from Latvia, the protest leader's sister, Tatsiana Khomich, said Kolesnikova had undergone surgery on Monday after a time in a punishment cell.
"For nearly two weeks her lawyer couldn't visit her, though this is a violation of her rights," said Khomich, described by TV Rain as a member of Babariko's team.
Nothing was known about the reason for the surgery, and Kolesnkova had not complained about her health, Khomich said. "It was really a bolt from the blue."
Khomich described her sister's condition as stable but serious and improving.
"It's possible, and I really hope so, that tomorrow there will be some details about why they operated, what happened when she was kept in the punishment cell, and again, why this information was not made available to her lawyer," she said.
Babariko's telegram channel said Kolesnikova was set to be moved out of the intensive care unit to a surgery ward on Wednesday.
"Our dear Masha (Maria), we all hope that you are going to be okay!" exiled opposition leader Sviatlana Tsikhanouskaya wrote on Telegram, describing the initial report of her hospitalisation as "awful news".
Kolesnikova, one of the leaders of mass street protests against Lukashenko in 2020, is serving an 11-year sentence for what she said were trumped-up allegations of involvement in mass unrest.
Khomich said she and her sister had last been allowed to talk on the phone in August but her father had been allowed to visit in late October for four hours. "Papa said Masha was in a very good mood, as always very strong, very cheerful."
Her sister, who famously tore up her passport to avoid being expelled in September 2020, when she was snatched from a Minsk street and driven by authorities to the Ukraine border, was forced to sew military uniforms seven hours a day, six days a week, Khomich added.
She also said that Kolesnikova suffered various punishments as a political prisoner, including having to wear a yellow label and being excluded from exercise and entertainment activities.
Asked why her sister had been placed in a punishment cell, she said Kolesnikova was accused of being in a work area during a non-work period and of having sworn at someone, which she denied.
The prison had special punishments for political prisoners, she added, including depriving them of gifts from relatives such as produce or clothing.
"Two weeks ago it became known that Maria's lawyer would lose his license," she added - the third of Maria's lawyers to have suffered such a fate.
Kolesnikova ran Babariko's presidential campaign when he sought to stand against Lukashenko in the 2020 presidential election that sparked mass protests crushed by a violent crackdown.
After Babariko was arrested in the run-up to the election - which Lukashenko duly claimed to have won by a landslide - Kolesnikova came out in support of Tsikhanouskaya.
(Writing by Tom Balmforth and Elaine Monaghan; Editing by Timothy Heritage and Gareth Jones)