Many Russian media outlets have been hacked, with anti-war messages being placed on their websites, as Russia continues its massive, unprovoked attack on Ukraine.

Twitter accounts historically associated with Anonymous, the amorphous online activist community that first grabbed global attention about a decade ago, claimed it was behind the hacker attack.

Among the media outlets impacted were websites of such news agencies and newspapers as TASS, Kommersant, Izvestia, Fontanka, Forbes, and RBK.

"[Russian President Vladimir] Putin forces you to lie and puts you in danger. Why do we need it? So that Putin was added to textbooks? This is not our war, let's stop him!" one of the messages read.

"This statement will be removed, and some of us will be fired or even jailed. But we cannot stand it anymore," the statement signed by "Not indifferent journalists" said.

The official website of the Kremlin was down on February 26, following reports of denial-of-service attacks on various other Russian government and state media websites.

Anonymous also claimed it was behind that cyberattack as well.