A spokesperson for the service told CNN that an SBU officer was killed in Kyiv and that an investigation into the assassination was under way. The SBU did not release any further details about the officer’s identity.

Silent CCTV footage purportedly showing the attack was shared on local Telegram channels.

CNN cannot independently verify the footage, but its location matches official photographs from the scene released by Kyiv Police.

The clip shows a man walking out of an apartment building in the Ukrainian capital in broad daylight.

He is seen carrying a couple of bags and heading towards a car parked nearby, when he is approached by a masked individual who appears to be holding a gun.

The attacker appears to fire the gun and the man with the bags collapses to the ground.

A bystander is seen running away from the scene.

The masked attacker then appears to fire again before fleeing the scene.

Kyiv Police has launched a manhunt, saying the perpetrator was “being identified”.

The police said it was investigating the crime in tandem with other law enforcement agencies.

It said the victim was found dead at the scene with a gunshot wound.

The SBU is Ukraine’s main security service.

Among others, it was responsible for Ukraine’s audacious drone attack against Russian airfields last month.

Dubbed “Operation Spiderweb,” Ukraine’s drone attack was a major success for Kyiv – and a major embarrassment for Moscow.

SBU operatives managed to smuggle dozens of drones deep into Russia, launching them from the vicinity of military airfields and taking Moscow by surprise.

Dozens of Russia’s military planes, including its strategic bombers and rare surveillance aircraft, were destroyed or damaged.

Ukrainian security sources have previously told CNN that the SBU were behind the assassination of Lieutenant General Igor Kirillov, who was wanted by Kyiv for alleged chemical weapons use.