Ukraine and Russia say their emergency alert apps have been hit by cyber-attacks - what we know in 100 words
In Ukraine, residents saw warnings including one for a "chemical threat" and another for "street fights"
Olena, who lives in Kyiv, tells BBC Radio 4's Today programme her "first thought" after seeing the alerts was: "I'm prepared for blackouts, for a cut in central heating and water supply, but not for a nuclear attack"
The air force went on to clarify there was no imminent threat of nuclear war, blaming Russian interference, writes our correspondent in Kyiv
Later, Russia itself said a "massive cyber-attack" had affected its app, with the emergencies ministry saying specialists were working to restore it
If this is confirmed as a tit-for-tat scenario, it implies whoever struck second had the power to carry out the hack but chose to hold off until its own system was hit, writes our cyber correspondent
Meanwhile, strikes were reported overnight in both countries, with four people injured in the Ukrainian city of Odesa and Russia saying drone strikes hit an industrial complex east of Moscow
The fake alert sent to Russia's emergency app had warned users that "nuclear warheads mounted on P1-Suns [a Ukrainian attack drone] had been launched at all regions of Russia".
The alert, which opened with a message telling residents there was a "risk of getting lively" also told them to "stock up urgently on food for three weeks and hide".
Image source, Getty ImagesEmergency alert apps in Ukraine and Russia have been hacked, according to reports.
The Ukraine government's Center for Strategic Communications has blamed Russia for the hack in a post on its X account, saying one of the alerts was a "message in Russian about Oreshnik".
A few hours later, Moscow also said that its emergency alert app had been hit by a "massive cyber-attack" - but did not immediately say who might be behind it.
Ukraine's Centre for Strategic Communications has blamed Russia for the hack in a post on its X account.
It posted a picture showing some of the alerts that had showed up on Ukraine's air raid warning app and asked residents to "disregard" any "strange messages" they might see in the app.
Image source, SPRAVDIThe Russian emergencies ministry says its public alert system is "operating as normal", stressing that citizens are informed of alerts through multiple channels including sirens and loudspeakers, text messages, and TV and radio broadcasts, and that the app is "only an additional, ancillary news service".
"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.
It said specialists were working to restore normal operation of the mobile app but the situation was "under control".
Abdujalil Abdurasulov
Ukraine reporter
The false warnings were sent out just minutes before the end of a ceasefire in the Ukrainian frontline city of Oleshky, which has been under Russian occupation since 2022.
The rare six-day ceasefire had allowed hundreds to evacuate from Oleshky, in a deal that was brokered with the help of US First Lady Melania Trump and Pope Leo XIV.
It was the longest a ceasefire has held since the start of Russia’s full-scale invasion.
But the fighting is likely to resume in Oleshky as both sides have accused each other of using this period to strengthen their frontline forces. And yet, the humanitarian mission has sparked some optimism.
Officials in Kyiv say that it can lead to "systemic solutions" and "pave the way for further steps in the peace process".
Yana Lantratova, who coordinated the Oleshky operation from the Russian side, says that both countries have agreed to carry out "regular humanitarian missions".
But as Vladimir Putin’s spokesperson puts it, the Kremlin sees such operations as separate from the peace process.
Image source, ReutersThe country's air force quickly responded after alarming false alerts on its air raid alert app for a short time said the capital Kyiv was subject to a radiation threat.
"The Air Alarm application has probably been subjected to hostile interference. There is no radiation threat! Stay calm and follow our updates on our channel," the air force said on Telegram.
The Ukrainian Central Intelligence Agency says there was a failure in the Air Alert app, and urges people to use other sources of information to clarify the situation on the threat of air strikes.
The app is supported by the Ministry of Digital Transformation of Ukraine, and informs users instantly about the beginning and end of defence alerts.
Ukraine and Russia are reporting cyber-attacks on their emergency alert apps, with fake warnings sent to users around the countries.
Ukraine was first to report problems, and for a short time the capital Kyiv was subject to a radiation threat, the Ukrainian Air Force has said.
A few hours later Russian authorities said its app was hacked, with a Ukrainian espionage group reportedly sending fake warnings of nuclear strikes inside Russia.
Stay with us as we bring you the latest developments.