The press office of opposition politician Viktor Babariko said Maria was hospitalized in the intensive care unit in Gomel in southeastern Belarus.
According to the statement, Kolesnikova, 40, was admitted to a surgical care unit on Monday, before being transferred to intensive care.
“Terrible news! Our dear Masha (abbreviated Maria), we all hope she is well,” Svetlana Tikhanovskaya, the exiled Belarusian opposition leader, wrote in Telegram.
Maria Kolesnikova, a leading figure in the protests against the Belarusian regime in the summer of 2020, was sentenced in September 2021 to 11 years in prison, after the Belarusian judiciary convicted her of plotting to seize power, violating national security and form an extremist formation.
Kolesnikova was jailed in September 2020 after resisting an attempted deportation from her country.
According to those close to her, the Belarusian secret services kidnapped her, then put a bag over her head to take her to the Ukrainian border. Refusing to leave Belarus, she jumped from a window and tore up her passport, forcing her to be locked up.
Kolesnikova was one of three women who led the protest movement, along with Svetlana Tikhanovskaya and Veronika Tsepkalo.
The last two fled the country under pressure from the authorities.
