Russian government websites, including the main Kremlin.ru and Duma.gov.ru sites, are experiencing intermittent outages.

The downtime comes after more than 100,000 Russian troops have invaded Ukraine. Leading up to, and coinciding with, the invasion, DDoS attacks took out Ukrainian government, bank, and media websites. Some cities also lost connectivity, potentially due to physical attacks on fiber and power infrastructure.

The downtime is likely due to a DDoS attack, with the Kremlin website occasionally throwing up the URL kremlin.ru/DDoS01/a622cf0c.

Update: "In addition to the DDoS attacks against Russian govt websites today, there were attempted DDoS attacks against the websites of major Russian banks as well," Doug Madory, director of Internet analysis at Kentik, said on Twitter. "Sberbank and Alfabank were targeted in consecutive DDoS attacks earlier today [Feb 24]."

Update February 25: The websites may appear down to international users, but are now online. In response to the DDoS attacks, Russia seems to have geofenced its websites, blocking them to external users.

Update, Feb 26: Cyberattacks have begun again, bringing down some Russian websites.

Original story continues: While the Russian government outages can be presumed to be related to this new war, it is not known who is behind the attack.

One possibility is a Ukrainian retaliation, or it could be a US act, after President Biden last year vowed to act aggressively on Russian cyberattacks, or the actions of another NATO country or Ukrainian ally.

It is even possible to be the actions of an independent actor - earlier this year it was revealed that a disgruntled US hacker brought North Korea offline after the country tried to hack him.

We will update this story as we learn more.