Ukrainians and Russians were sent false nuclear attack warnings after they were hit by a massive cyberattack.
Issues were first reported by Ukraine’s Air Force, after fake radiation alerts were sent via its public air raid app.
The app for a short time showed Kyiv and other areas subject to a nuclear warning.
But the abnormality later disappeared, the Ukrainian military said on Sunday night.
Moscow later reported that a ‘massive cyber attack’ had affected its app but insisted its wider alert system is ‘operating as normal’.
A Ukrainian espionage group was blamed for sending fake warnings of nuclear strikes inside Russia; however, the Ukrainian government’s Centre for Strategic Communications blamed Russia for the hack on its X account, saying one of the alerts was a ‘message in Russian about Oreshnik’.
The Ukrainian air force said on Telegram: ‘The air alert app appears to have been subjected to enemy influence.
‘There is no radiation threat! Stay calm and follow our updates on our channel!’
The fake alerts began on Sunday night, warning Ukrainians about radiation and chemical threats. Pictured: A screenshot of the notifications sent out in Ukrainian
The alleged hack came minutes after the end of the truce between Moscow and Kyiv in the eastern region of Kherson. Pictured: Ukrainians hug each other after being evacuated from the temporarily Russian-occupied city of Oleshky, Kherson region
When asked whether the app had been hacked, Ukrainian air force spokesman Yuriy Ignat said: ‘Yes, it has been.’
The Ministry of Digital Transformation of Ukraine supports the app, which informs users instantly about the start and end of defence alerts.
The bogus warnings were sent out just moments before the end of a six-day ceasefire in Oleshky, which has been occupied by Russia since 2022.
Hundreds of citizens had been allowed to evacuate from Oleshky, thanks to a deal brokered by US First Lady Melania Trump, with support from Pope Leo XIV.
The warnings were followed by all-clear messages just over an hour later.
Meanwhile, a fake alert sent to Russia’s emergency app warned users that nuclear warheads on Ukrainian attack drones had been launched at all regions of Russia.
The alert urged Russians to urgently stock up on food for three weeks and to hide.
The warning read: ‘Nuclear warheads have been launched on P1-SUN carriers across all regions of Russia!
‘Urgently stock up on food for three weeks and hide in your basement, otherwise you will be blown to bits.’
The P1-SUN is a Ukrainian non-nuclear interceptor drone deployed to down Russian unmanned aircraft. Ukraine does not have atomic weapons.
The false warnings were reported in Moscow, St Petersburg, Belgorod, Nizhny Novgorod, Tyumen, Tula and Chelyabinsk, as well as Perm, Stavropol and Bashkortostan.
Russia’s Emergency Situations Ministry publicly acknowledged a massive cyberattack.
It claimed the country’s sirens, loudspeakers, television and radio warning systems had not been compromised.
The ministry was working to restore normal service.
As of 2.30am, UK time, on Monday, Russia’s app was still down – but leaders insisted its wider alert system was still working.
‘The hacking of the mobile app has not had, and cannot have, any impact on the operation of the public alert system,’ it said on its Telegram channel.
The alleged hacks came just minutes after the end of the truce between Moscow and Kyiv in the eastern region of Kherson.
The localised ceasefire, which started on Tuesday, was the longest of the war.
The Ukrainian Centre for Countering Disinformation has warned: ‘Currently, the information broadcast (on this application) about threat levels does not correspond to reality.’
The app is used across Ukraine to warn people in real time of the threat of air strikes from Russia.
People often have only minutes to find shelter in the case of, for example, a ballistic missile attack.
SPRAVDI, Ukraine’s Center for Strategic Communications, blamed Russia for the hack in a post on its X account.
A separate app, which deals specifically with the Ukrainian capital, is still working normally, the Kyiv city authorities said.
The BBC reports that the messages started at around 10.47pm local time tonight. The first read: ‘Radiation threat. Radiation threat declared in Kyiv.’
The next alert, sent one minute later, warned: ‘Hi! There will be a nuclear alert across Ukraine. Don’t worry, it’s Oreshnik flying.’
A third message, delivered at 10.49pm, said: ‘Chemical threat. There is a threat of a chemical attack on Kyiv. Don’t go outside.’
A fourth, sent seconds later, stated there was a ‘Street fighting threat. Street fighting is taking place in Kyiv. Don’t go outside.’
Multiple all-clear messages were then sent out.
Russia and Ukraine also exchanged strikes targeting each other’s energy infrastructure overnight.
Russia said drone strikes hit an ‘industrial enterprise’ east of Moscow, which Ukrainian media identified as the Kstovo oil refinery.
Meanwhile, Russia’s Ministry of Defence said it struck a Ukrainian military cargo vessel at sea 36miles south of Odesa overnight.
In a Telegram post, it said the vessel was ‘delivering cargo intended for the Ukrainian Armed Forces’.
Another strike hit a storage site for Ukrainian missile launch systems in the Odesa village of Tuzly, it added.
Meanwhile, a Telegram channel for the city of Odesa said four people were injured in strikes in Odesa overnight.
It comes after the longest truce of the war, limited to the eastern Kherson region, ended on Sunday after Russia refused the offer of an extension, according to Ukrainian officials.
The rare pause in fighting, brokered by US First Lady Melania Trump and which began early Tuesday, enabled a humanitarian mission to the Russian-occupied city of Oleshky as the war grinds through its fifth year.
Neither side reported violations after the truce began, in what one Ukrainian lawmaker described as the ‘biggest de-escalation since 2022’.
‘The ceasefire, which was in effect from October 27 to November 1, has ended,’ said Ukraine’s Parliament Commissioner for Human Rights, Dmytro Lubinets.
He called the temporary truce ‘an important step in our joint humanitarian efforts’ with Russia.
An estimated 2,000 civilians were in Oleshky when the temporary truce took hold.
They were offered the choice of evacuating to territory controlled by Ukraine or Russia, or remaining in the city with replenished food and medical supplies.
For the safety of those who have stayed, exact numbers were not released after the evacuation.
At the Ukrainian border on Saturday, family members waited for a glimpse of their loved ones, while residents of nearby villages lined the highway waving flags and flashlights to greet the humanitarian convoy.
But Moscow and Kyiv have continued aerial strikes elsewhere, with Ukrainian President Volodymyr Zelensky saying on Sunday that Russia continues to target Ukraine’s energy systems ahead of winter.
US-mediated talks between Russia and Ukraine are set to resume this month, having been effectively frozen since the United States and Israel launched joint strikes on Iran in February.
– This is a developing story, more to come.
