U.S. believes Russian intelligence was behind attack on journalist

Dmitry Muratov, editor of the investigative newspaper Novaya Gazeta, has said that while he was on a train he was splashed with red paint containing acetone by an attacker who told him, "this is for you from our boys."

Muratov at the time posted photographs of his face, chest and hands covered in red oil paint, which he said badly burned his eyes because of the acetone.

Novaya Gazeta announced before the attack that it was suspending its online and print activities until the end of what Russia calls its "special operation" in Ukraine.

The Russian government had twice warned the paper over its coverage of the conflict, which Russia says is aimed at degrading Ukraine's military capabilities and rooting out what it calls dangerous nationalists.

Ukrainian forces have mounted stiff resistance and the West has imposed sweeping sanctions on Russia in an effort to force it to withdraw its forces.