Ukraine’s president accused the Kremlin of “state terrorism” after a fugitive Russian MP who had denounced the annexation of Crimea was gunned down in the centre of Kiev.

Denis Voronenkov, a former member of the State Duma, Russia's lower house, was shot dead near an upscale hotel as he set off for a meeting with another Kremlin critic on Thursday morning.

The attacker also wounded Voronenkov’s bodyguard, who shot back and injured the assailtant. Police said both were “critically ill” in hospital.

President Petro Poroshenko said the killing "is an act of state terrorism on the part of Russia, which (Voronenkov) was forced to leave for political reasons."