WATCH the moment the leader of the opposition in Russia Alexei Navalny fell ill during a flight to Moscow.
In the footage Alexei Navalny appears to be screaming in pain before he is escorted off a plane by medical staff. Mr Navalny is currently in a serious but stable condition in an intensive care unit.
Kira Yarmysh, the press secretary for Mr Navalny's party Anti-Corruption Foundation, tweeted: "This morning Navalny was returning to Moscow from Tomsk.
"During the flight, he felt ill.
"The plane made an urgent landing in Omsk.
"Alexei has toxic poisoning."