Kremlin critic Alexei Navalny detained upon return to Russia

But the 44-year-old opposition politician laughed and joked with journalists on his plane, saying he was not afraid and did not believe he would be arrested.

In the event, he was swiftly detained when he showed his passport to border guards before formally entering Russia, Reuters witnesses said. His wife, Yulia, his spokeswoman, and his lawyer were allowed to enter Russia.

FSIN said in a statement Navalny had been detained due to the alleged violations of his suspended prison sentence and would be held in custody until a court hearing later this month that will rule whether to convert his suspended sentence into a real 3.5 jail term.

Navalny, one of Putin’s most prominent domestic critics, faces potential trouble in three other criminal cases too, all of which he says are politically motivated.

Navalny says Putin was behind his poisoning. The Kremlin denies involvement, says it has seen no evidence that he was poisoned, and that he was free to return to Russia.

Navalny says the Kremlin is afraid of him.

The Kremlin, which only refers to him as the “Berlin patient”, laughs that off. Putin allies point to opinion polls that show the Russian leader is far more popular than Navalny, whom they call a blogger rather than a politician.

European Union members Lithuania, Latvia and Estonia called for the “imposition of restrictive measures” against Russia following Navalny’s arrest.

Navalny took a flight operated by Russian airline Pobeda, owned by state-controlled Aeroflot.

His supporters gathered at Moscow’s Vnukovo airport despite a forecast of bitterly cold minus 22 degrees Celsius (minus 7.6 degrees Fahrenheit) weather and over 4,500 new coronavirus cases a day in the Russian capital.

The authorities’ decision to switch airports to Sheremetyevo airport, ostensibly for technical reasons, thwarted them.

OVD-Info, a monitoring group, said police had detained 53 people in Moscow and five in St Petersburg.

The Moscow prosecutor’s office, which had officially warned 15 pro-Navalny organisers, had said meeting him en masse was illegal because it was not sanctioned by the authorities.