Gravely ill Kremlin critic Alexei Navalny was evacuated to Germany for medical treatment on Saturday, flown out of the Siberian city of Omsk in an ambulance aircraft and taken to a hospital in Berlin.
A long-time opponent of President Vladimir Putin and campaigner against corruption, Navalny collapsed on a plane on Thursday after drinking tea that his allies believe was laced with poison.
The air ambulance landed on Saturday morning at Berlin's Tegel airport and Navalny, 44, was rushed in a convoy of ambulance and police cars to the city's Charite hospital complex.
The hospital gave no details about his condition but said in a statement it would provide an update about this and further treatment once tests have been completed and after consulting with his family. It added this could take some time.
Medical staff at the Omsk hospital said on Friday evening, before Navalny was flown out, that he was in an induced coma and his life was not in immediate danger.
German doctors flew to Omsk on Friday to evacuate Navalny at the request of his wife and allies who said that the hospital treating him was badly equipped. But there was then a delay flying him out as the hospital initially said he was not in a fit state to travel.
"The flight carrying Alexei Navalny has arrived in Berlin... He is in stable condition," the Cinema for Peace Foundation, which sent the air ambulance, said in a statement.
The organisation's founder, Slovenian-born activist and filmmaker Jaka Bizilj, was also quoted by Bild as saying his condition was stable during the flight and after landing.
Kira Yarmysh, Navalny's spokeswoman, said on Twitter that "This is another proof that nothing was preventing Navalny from being transported, and it was necessary to do so as early as possible."
Two years ago, Pyotr Verzilov, another anti-Kremlin activist and a member of the Pussy Riot art collective, was treated at the Charite hospital after he was poisoned in Moscow.
Cinema for Peace said Navalny's family would issue a statement in the coming days once it knew more about his condition. Yarmysh, Navalny's spokeswoman, said the opposition politician's wife Yulia was on board the evacuation flight.
Omsk doctors said on Saturday they were ready to share all information they have with the German clinic.
Navalny's allies have said they feared authorities in Russia might try to cover up clues as to how he fell ill.
Navalny has been a thorn in the Kremlin's side for more than a decade, exposing what he says is high-level graft and mobilising crowds of young protesters.
Medical staff at the Omsk hospital initially said on Friday that Navalny's condition had improved slightly overnight but he was in too unstable a state to be safely flown out of the country.
They later said they had no objections after the German doctors deemed him fit for travel.
Navalny's wife sent a letter to the Kremlin directly appealing for it to intervene and grant permission for him to be allowed to be flown out.
Navalny has been repeatedly detained for organising public meetings and rallies and sued over his investigations into corruption. He was barred from running in a presidential election in 2018.