Russian opposition leader Alexei Navalny holds a news conference in his campaign office in St. Petersburg, Russia, Feb. 4, 2017.
Russian opposition leader Alexei Navalny holds a news conference in his campaign office in St. Petersburg, Russia, Feb. 4, 2017.

MOSCOW - Opposition leader Alexei Navalny has been doused in bright green liquid by an unknown assailant in the Siberian city of Barnaul.

Navalny tweeted Monday: "I will be opening a headquarters in Barnaul as if I am from the film The Mask! Cool. Even my teeth are green!" He was referring to the Hollywood film that features a superhero who wears a green mask.
 
The green liquid, a common Russian antiseptic that remains on skin for days, was reportedly sprayed in Navalny's face as he went to shake a man's hand.
 
Navalny is currently traveling around Russia opening headquarters and campaigning to stand in the 2018 presidential elections. A criminal conviction for fraud officially bars him from running, but supporters say the charges are politically motivated.