Millions of Russians were today told to rush to air raid shelters because of an imminent missile attack after radio stations were (apparently) hacked.
The emergency message came on many commercial stations in cities across at least four time zones in Russia.
Interrupting programs with a siren, the spoof warning claimed: 'An air alert is being announced. Everyone, go to the shelters immediately. Attention! Attention! There is a threat of a missile strike.'
Among the cities affected were Belgorod, Stary Oskol, Ufa, Kazan, Novouralsk, Novosibirsk, Pyatigorsk, Tyumen, Voronezh, Nizhny Novgorod and Magnitogorsk as well as a number of places in the Moscow region.
Some local authorities blamed Ukraine for the hacking attack but it is unclear where it came from.
The regional government in Belgorod, which borders Ukraine, said: 'Information about a missile strike and an air alert on one of the radio frequencies in Belgorod is fake.
'One of the radio stations on the morning of February 22 was hacked, presumably from the Ukrainian side.'
The Russian emergencies ministry said: 'A hacker attack on the servers of several commercial radio stations in some regions of the country resulted in the airing of information about an alleged air raid alert and the threat of a missile strike.
'The Russian emergencies ministry reports that this information is fake and does not correspond to reality.'
Among the stations hit across different regions were Energy FM, Relax FM, Business FM, Humor FM and Autoradio.
Yuri Peryazev, the head of the civil defense and emergency situations in the Sovetsky district, Novosibirsk, denied any missile strikes.
He added: 'We're doing fine. There is no air alert.'
A spokesman for Gazprom Media, which runs several of the hacked stations, said: 'We are dealing with this issue.
'This will not happen again in the near future.'
