The messages warned of possible nuclear radiation in the capital.

Hackers have sent false warnings of a possible nuclear attack to people in Ukraine after breaking into a public emergency alert application. The messages caused concern among residents, but Ukrainian authorities quickly reassured the public that there was no radiation or nuclear threat.

The incident took place late on Sunday, 1 November 2026, when Ukraine's air raid alert application began sending alarming notifications to users in Kyiv and other parts of the country. The messages warned of possible nuclear radiation, a chemical attack and even street fighting in the capital.

According to Reuters, one of the false messages claimed that Russia had launched its Oreshnik hypersonic missile, which is capable of carrying a nuclear warhead. The warning also suggested that a nuclear alert had been declared across Ukraine.

Ukraine's Air Force responded quickly, telling people that the application appeared to have been hacked. It urged residents to remain calm and confirmed that there was no radiation threat. The authorities also advised people to follow official updates rather than believe the false notifications.

[The Guardian](https://www.theguardian.com/world/2026/nov/02/hackers-fake-nuclear-chemical-threat-alert-kyiv-ukraine-emergency-app) reported that some residents initially ignored the warnings because they suspected that the application had been compromised. However, others were frightened by the messages. One woman told the newspaper that she was briefly terrified after receiving the alert.

The Ukrainian emergency service later confirmed that unauthorised parties had interfered with the application. Its alert channel was temporarily suspended, and users were warned not to click on links included in suspicious notifications.

[The BBC](https://www.bbc.com/news/articles/cwx28mngxz8do) also reported on the incident, highlighting the false warnings received by people in Ukraine and the authorities' efforts to reassure the public. Reports indicated that the messages included unusual wording and spelling mistakes, which raised further doubts about their authenticity.

Officials stressed that the cyberattack had not affected the country's wider security and emergency response systems. Air raid sirens and other methods of warning the public continued to work. People were advised to rely on trusted government announcements for accurate information.

Interestingly, the incident was not limited to Ukraine. Reuters reported that Russia's emergency ministry also said its mobile application had been targeted in a separate cyberattack. The breach reportedly resulted in false warnings about nuclear attacks and other threats being sent to Russian users.

It was not immediately clear who was behind the attacks or whether the two incidents were connected. Reuters said it could not independently verify which groups were responsible.

The cyberattacks came at a sensitive time in the ongoing war between Russia and Ukraine, highlighting the growing importance of digital security during the conflict.

Although the false alerts did not reflect a real nuclear threat, the incident has raised concerns about the safety of emergency communication systems. Such applications play an important role in warning civilians about incoming attacks and helping them reach safety.

Ukrainian authorities have urged residents to stay calm, avoid sharing unverified messages and follow information released through official channels. The incident serves as a reminder that false information spread through hacked emergency systems can create fear and confusion, particularly in a country already facing the dangers of war.