Ukrainian hackers carried out a cyberattack that took down online broadcasts of Russian state television and radio channels on Monday, according to an official in Kyiv with knowledge of the operation.

By Dmitry Antonov and Andrew Osborn MOSCOW (Reuters) -Russian state media company VGTRK, which owns and operates the country's main national TV stations, was targeted in a massive cyberattack on Monday that a Ukrainian government source said Kyiv's hackers had caused.

Ukrainian hackers made a “gift” to Russian President Vladimir Putin on his birthday by launching a large-scale attack on the all-Russian state television and radio broadcasting company. Cyber specialists stopped online broadcasts of Russia 1 and Russia 24 TV channels.

Vladimir Putin was gifted an unwelcome birthday present today by Ukrainian hackers who took down Russia's state media company - leaving websites and live TV feeds blacked out for hours. VGTRK, which owns and operates the country's main national TV stations,

The Kremlin said on Monday that state media holding VGTRK had been targeted in what it called an unprecedented hacking attack and that the company was working had to try to overcome the consequences.