Kiev: A prominent Russian journalist and critic of President Vladimir Putin was gunned down in Ukraine where he had fled into exile following threats, police said on Tuesday.

Arkady Babchenko died of his wounds in an ambulance after his wife found him covered in his blood in their home, police said, adding they suspected the murder was due to Babchenko's professional activities.

Babchenko, one of Russia's best-known war correspondents, had left Russia fearing for his life after criticising Russian policy in Ukraine and Syria.

He had been denounced by pro-government politicians in Russia over comments on social media about the Russian bombing of Syria, and over his characterisation of Russia as an aggressor towards Ukraine.

"The first version is his professional activity," said Kiev police chief Andriy Kryshchenko on the TV news channel 112, when asked what police suspected lay behind the murder.

Two years ago, Pavel Sheremet, a Belarussian journalist known for his criticism of his home country's leadership and his friendship with the slain Russian opposition leader Boris Nemtsov, was blown up in a car bomb in central Kiev.

"Putin's regime is aimed at those who cannot be broken or intimidated," Anton Gerashchenko, a Ukrainian lawmaker and advisor to the interior minister, wrote on Facebook. "Today in Kiev on the threshold of the apartment where he lived, a famous Russian journalist Arkady Babchenko was shot and killed, a consistent opponent of the Putin regime and a friend of Ukraine."

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