Moscow blames Kyiv for a series of car bombings that have targeted people linked to the war with Ukraine.

A car bombing in Moscow has critically injured an adviser to Ukraine’s former prime minister a day after a similar attack killed a military officer in St Petersburg.

The explosion on Friday was the latest in a series of bombings and shootings that have targeted people involved in the fighting in Ukraine. Moscow has blamed Kyiv for the attacks.

The Moscow explosion struck a car driven by Sergei Zavorotnyi, who previously worked as an adviser to former Ukrainian Prime Minister Mykola Azarov, according to Russia’s Investigative Committee.

Zavorotnyi was hospitalised with injuries, the committee added. It did not identify possible suspects pending a criminal inquiry.

Azarov served as prime minister under Ukraine’s Moscow-friendly President Viktor Yanukovych, who was forced from office by protesters and fled to Russia in February 2014.

Azarov, who also lives in Russia, told state-run TV that he was “shocked” by the attack that left his former adviser critically injured. He said he believes Zavorotnyi was targeted because of his criticism of the Ukrainian government.

Zavorotnyi. 72, had worked as a journalist for Russia’s daily Komsomolskaya Pravda before becoming Azarov’s adviser. He wrote a book about Yanukovych’s ouster and ran an online outlet critical of Ukrainian authorities.

Russia’s REN TV channel said he lost his left arm, suffered multiple other injuries and was in a coma after the explosion.

Explosive devices triggered remotely

Al Jazeera’s Yulia Shapovalova, reporting from Moscow, said an explosive device was reportedly planted under the man’s car and detonated remotely as he was driving on Friday.

“The investigative committee has already launched a criminal case into this explosion,” she said.

A day earlier, in St Petersburg, a military serviceman was killed by a bomb in his vehicle, according to Russia’s Investigative Committee. It did not identify the victim or say who could be behind the bombing.

The Fontanka news outlet said Thursday’s victim was a colonel, while other Russian online media said the victim was a senior air force officer.

Shapovalova said preliminary reports indicated that the victim was a military serviceman, rather than a colonel of the Russian Air Force.

Like the attack on Friday, he was also driving the car when the bomb went off, she added.

“In both cases an explosive device was triggered remotely, and it was planted under their car,” Shapovalova said. “Here in Russia, all the attacks are considered to be orchestrated by the Ukrainian side.”

Ukrainian authorities have not commented on either bombing.