Responsibility for the cyberattack was claimed by a Ukrainian hacker group called Silent Crow along with a Belarusian hacker activist group known as the Cyber-Partisans.

A cyberattack on Russian state-owned flagship carrier Aeroflot caused a mass outage to the company’s computer systems on Monday, Russia’s prosecutor’s office said, forcing the airline to cancel more than 100 flights and delay others.

The hack may have been part of a campaign to disrupt the sense of normalcy Russians have mostly enjoyed since the start of the war.