The Russian opposition leader, who had been recovering in Germany since August from a near-deadly poisoning, was arrested on Sunday night at passport control at Sheremetyevo Airport in Moscow.
The police also detained some of his supporters who had turned out to greet him at the airport.
Russia’s penitentiary service, which has said that Mr. Navalny was wanted for violating the terms of a prior suspended sentence, released a statement saying that he had been detained pending a court hearing.
Minutes before he was taken into custody, Mr. Navalny gave an impromptu statement to journalists in a transit area at the airport terminal. “I am not afraid,” he said. “I know that I am right. I know all the criminal cases against me are fabricated.”
His arrest could set off protests and an international backlash. He has accused the Kremlin of trying to murder him in YouTube videos viewed more than 40 million times.❐