Gravely ill Kremlin critic Alexei Navalny has been evacuated to Germany for medical treatment, flown out of the Siberian city of Omsk in an ambulance aircraft and taken to a hospital in Berlin.
There is no word yet from the Charite hospital on his condition but the founder of the activist group that arranged the flight called Mr Navalny's health condition "very worrying".
A long-time opponent of President Vladimir Putin and campaigner against corruption, Mr Navalny collapsed on a plane on Thursday after drinking tea his allies believe was laced with poison.
Medical staff at the hospital in Omsk said on Friday evening after clearing Mr Navalny to be flown out that he was in an induced coma and his life was not in immediate danger.
The air ambulance, arranged by the Cinema for Peace Foundation, flew to Berlin early on Saturday and Mr Navalny, 44, was rushed to the Charite hospital complex.
The hospital said in a statement it would provide an update about his condition and further treatment once tests have been completed and after consulting with his family.
A view of the Charite clinic in Berlin, Germany, where Alexei Navalny is undergoing treatment. Source: EPA
A spokeswoman for Charite said later it was unlikely the hospital would give a statement on Mr Navalny over the weekend.
Cinema for Peace founder Jaka Bizilj, speaking to reporters outside the hospital, said "his health condition is very worrying".
"We got a very clear message from the doctors that if there had not been an emergency landing in Omsk, he would have died," said Mr Bizilj, adding that it would be up to doctors and Navalny's family to provide further information.
Mr Bizilj, a Slovenian-born activist and filmmaker, was earlier quoted by Bild tabloid as saying Mr Navalny's condition was stable during the flight and after landing.
Kira Yarmysh, Mr Navalny's spokeswoman, said on Twitter: "This is another proof that nothing was preventing Navalny from being transported, and it was necessary to do so as early as possible."
German doctors flew to Russia on Friday to evacuate Mr Navalny at the request of his wife and allies who said the hospital treating him was badly equipped.
Russian opposition activist Alexei Navalny. Source: AP
But there was then a delay flying him out as the Omsk hospital initially said his condition meant he could not travel.
Mr Navalny's allies say they fear authorities in Russia might try to cover up clues as to how he fell ill.
Mr Navalny has been a thorn in the Kremlin's side for more than a decade.
