Ukrainian officials said the country’s official air-raid alert app was likely compromised after residents in Kyiv received bogus warnings Sunday about a radiation emergency and a chemical attack.
The misleading notifications instructed people to remain indoors and avoid going outside.
“Radiation hazard alert in Kyiv. Do not go outside!” one message stated.

Russian intelligence-linked cyber actors have targeted thousands of commercial messaging apps, according to a public service announcement jointly released by the FBI and CISA on Friday. (Photo by Morteza Nikoubazl/NurPhoto via Getty Images)
A second notification warned: “Chemical attack alert in Kyiv. Do not go outside!”
The online public air-raid map also showed Kyiv and other regions under a nuclear alert. Additional fabricated messages referenced Russia’s hypersonic Oreshnik missile and claimed that street battles were taking place in the capital.
Street loudspeakers also broadcast a recorded announcement telling residents to take protective measures.
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Fire rises over a city administration building partially destroyed by a Russian airstrike on November 1, 2026, in Kramatorsk, Ukraine. (Alex Nikitenko/Global Images Ukraine via Getty Images)
Ukraine’s Air Force later said the air-alert system had been hacked and stressed that there was no radiation emergency.
“The air-alert app appears to have been subjected to hostile interference. There is no radiation threat. Remain calm and follow updates on our channel,” the Air Force said in a statement shared on Telegram.
Ukraine’s Center for Strategic Communications accused Russia of being behind the disruption, though no group had publicly claimed responsibility.

Teenagers look out over Kyiv during a partial power outage following Russian attacks on October 31, 2026. (Tetiana DZHAFAROVA / AFP via Getty Images)
Separately, Russia’s Emergencies Ministry said early Monday that its mobile app had been struck by a “massive cyberattack,” allowing attackers to distribute false information to the public.
“Attention! The mobile application of Russia’s Ministry of Emergencies has been subjected to a massive cyberattack, enabling attackers to send false information to the public,” the ministry said on Telegram.