Kyiv: Ukraine and Russia reported cyberattacks on their public emergency warning applications on Sunday and Monday, with users receiving false notifications about nuclear strikes, radiation exposure and other threats.
The incidents occurred as a six day local ceasefire in southern Ukraine neared its end.
Ukraine's air force said its widely used Air Alert application began displaying fabricated warnings shortly before 11 pm on 1 November, affecting Kyiv and several other regions.
The notifications warned of radiation exposure, chemical attacks and possible fighting in residential areas. One message falsely stated that Russia launched an Oreshnik missile, which is capable of carrying a nuclear warhead.
Ukrainian authorities suspected external interference and reassured residents that there was no radiation threat.
The Ministry for Digital Transformation temporarily suspended the affected application while investigations began. Officials said conventional air raid sirens and other public warning systems remained operational.
Russia reports similar cyberattack
Hours after the Ukrainian incident, Russia's Emergencies Ministry reported a major cyberattack on its own mobile warning application.
Russian authorities said attackers distributed fabricated notifications suggesting that nuclear weapons were launched against Russian regions.
Some messages also urged residents to stockpile supplies and seek shelter.
The ministry said the compromised application was a supplementary information service, not the country's primary emergency warning system. It maintained that the main public alert infrastructure continued functioning normally.
Reuters reported that the pro Ukrainian group Atesh shared an image of one of the fabricated Russian alerts. However, the news agency could not independently establish who was responsible for either attack.
Although Ukrainian officials suspected Russian involvement, no independently verified evidence established the perpetrators or confirmed whether the two incidents were connected.
Attacks coincide with Kherson ceasefire ending
The cyberattacks occurred as a six day local ceasefire in the southern Kherson region expired.
According to a Reuters report, the temporary arrangement enabled hundreds of civilians to evacuate Oleshky, a town under Russian occupation since 2022.
The humanitarian pause was reportedly negotiated with assistance from US First Lady Melania Trump and Pope Leo XIV.
The ceasefire was limited to a specific area and did not constitute a nationwide suspension of hostilities.
Ukrainian officials said the arrangement demonstrated the possibility of further humanitarian cooperation, although Russia continued to distinguish such operations from broader negotiations to end the war.
Concerns over emergency communication systems
Emergency alert applications are widely used in Ukraine, where civilians regularly receive warnings about incoming missiles and drones.
Interference with these systems can undermine confidence in official emergency communications, particularly when fabricated alerts concern nuclear or chemical threats.
The incidents highlighted cybersecurity risks facing civilian digital infrastructure during the conflict.
However, no verified evidence shows the attacks were coordinated or linked to the expiry of the ceasefire in Kherson.
Authorities in both countries said alternative warning channels remained operational, while investigations and technical recovery efforts continued.
