A car bombing in Moscow on Friday critically injured Sergei Zavorotnyi, an adviser to Ukraine's former prime minister Mykola Azarov, according to Russia's Investigative Committee. An explosive device was planted under his vehicle and detonated remotely as he drove, Al Jazeera reported. Zavorotnyi, 72, was hospitalised with severe injuries. REN TV reported he lost his left arm, suffered multiple other injuries and was in a coma.

The attack followed a similar bombing a day earlier in St Petersburg that killed a military serviceman in his vehicle. Russia's Investigative Committee said an explosive device was triggered remotely in that case as well.

Moscow has blamed Kyiv for the bombings and other recent attacks targeting people linked to the war with Ukraine. Ukrainian authorities have not commented on either attack.

Azarov told Russian state-run TV he was "shocked" by the assault on his former adviser. He said he believes Zavorotnyi was targeted because of his criticism of the Ukrainian government. Zavorotnyi previously worked as a journalist and ran an online outlet critical of Ukrainian authorities. Azarov served as prime minister under Viktor Yanukovych, who fled to Russia in 2014 after protesters forced him from office.