Ukraine's Air Force stated that its air raid alert application issued erroneous warnings on Sunday, including nuclear threats, chemical threats, and street fighting alerts, and falsely mentioned the deployment of Russia's "Oreshnik" hypersonic missile, following a suspected Russian cyberattack. Ukraine's Center for Strategic Communications (SPRAVDI) accused Russia of launching the attack on X. Hours later, early on Monday, Russia's Ministry of Emergency Situations also reported that its mobile application had suffered a "massive cyberattack," leading to the spread of false information. The statements from both countries came as a week-long ceasefire in the Kherson region had just concluded.