Ruslan Leviev, founder of Conflict Intelligence Team, a blogging group that focuses on Russian military and mercenary activity, said in a post on November 27 that he was walking home when a man came up to him, hit him in the jaw, and splashed him with the dye.

He posted pictures of himself on Facebook with green dye on the right side of his face and hands as he washed it off.

Leviev said the attack was most likely "revenge" for his previous activities.

Moscow police did not immediately respond to a request for comment on Leviev.

If confirmed, the attack would echo those made in 2017 against Kremlin opponent Aleksei Navalny, who was briefly hospitalized after he was hit in the face by green dye twice in a five-week period. It was not clear who carried out the attacks.

The green liquid, known as "zelyonka," is sold in pharmacies as an antiseptic and is difficult to wash off.

In 2017, Ilya Varlamov, a well-known blogger focusing on corruption issues, was attacked in Stavropol by men who pelted him with zelyonka, eggs, and flour.

With reporting by Reuters