Russian journalist and Nobel laureate Dmitry Muratov has been attacked on a train from Moscow to Samara by a person who poured red paint over him.
The attacker must have poured oil paint with acetone into his compartment.
According to Muratov, the man shouted "Muratov, this is for our boys".
"My eyes are burning terribly (...) The smell of oil all over the car," Muratov wrote in a statement after the attack.
Muratov, editor-in-chief of the independent newspaper Novaya Gazeta, was awarded the Nobel Peace Prize last year.
The newspaper ceased operations at the end of March this year.