German Foreign Minister Annalena Baerbock on Wednesday called for the immediate release of jailed Belarusian opposition leader Maria Kolesnikova, who has been admitted to intensive care in hospital.
"I am deeply affected by the reports on the condition of Maria Kolesnikova," Baerbock tweeted.
"The regime in Belarus must take responsibility for her health and release her immediately. Her engagement for democracy is not a crime."
The press service of fellow opposition politician Viktor Babaryko said on Tuesday that Kolesnikova, who is serving a long prison term, was in the intensive care unit of an emergency hospital in Gomel in southeastern Belarus.
The team posted on Wednesday on Telegram that they had been "waiting for news all night and morning".
"At the moment, the emergency services of the Gomel Hospital aren't answering phone calls. We hope that the doctors in Gomel are providing Masha with all the quality care she needs," the press service said.
In the same post, her sister Tatyana Khomich is quoted as saying: "We want to know the truth about her health and the reasons for her hospitalisation."
The United States, which has helped lead criticism of Belarusian strongman Alexander Lukashenko, voiced hope that Kolesnikova fully recovers.
Uzra Zeya, the US under secretary of state in charge of human rights, said the United States condemned the "horrific abuses" against Kolesnikova "and the other 1,400+ political prisoners in Belarus."
"Perpetrators will be held to account," Zeya tweeted.
Kolesnikova was part of a trio of women -- with Veronika Tsepkalo and Svetlana Tikhanovskaya -- who led historic demonstrations against Lukashenko.
Kolesnikova, 40, is the only one of the three still in the country, but she is serving 11 years for conspiracy over her role in the mass protests.
According to the press release on Tuesday, she first went to the surgery unit before being sent to intensive care.
Last week Babaryko's press service said Kolesnikova had been put in solitary confinement on the grounds of "impolite behaviour".
It said her lawyer had been denied access to Kolesnikova.
In 2020 massive rallies had broken out across Belarus, against Lukashenko's claim to a sixth presidential term.
Lukashenko cracked down on the protests, leading to thousands of arrests and the forced exile or imprisonment of activists and journalists.
Western countries have adopted several sets of sanctions against Minsk, which has Moscow's unwavering support.
Russia used Belarus as a launching pad for its military operation in neighbouring Ukraine on February 24, but the Belarusian army has not officially taken part in fighting on Ukrainian territory.
