Putin critic Alexei Navalny in ICU after Russia poisoning — aide

Russian opposition leader Alexei Navalny is in the intensive care unit of a Siberian hospital after being left unconscious from a poisonous toxin believed to have been mixed in his tea, his press secretary Kira Yarmash tweeted Thursday.

Why it matters: The anti-corruption lawyer is the face of Russia's domestic opposition to President Vladimir Putin. His activism has led to him being targeted by authorities in raids and jailed dozens of times. Navalny was hospitalized in 2019 after his doctor said he was poisoned with "undefined chemical substances."

Details: Yarmash said Navalny felt ill on a flight from Tomsk to Moscow and the plane made an emergency landing in the city of Omsk, where he was taken to hospital, per a Twitter translation.

"We assume that Alexei was poisoned with something mixed into the tea," her statement said. "It was the only thing that he drank in the morning. Doctors say the toxin was absorbed faster through the hot liquid. Alexey is now unconscious."

An Omsk Emergency Hospital spokesperson described the 44-year-old's condition to Russian news agency Tass as "serious."

Editor's note: This article has been updated with new details throughout.