Warning: Graphic footage

Shocking surveillance video verified by CNN and the BBC shows Russian soldiers shooting two civilians in the back, providing a stark example of a potential war crime by Russian forces invading Ukraine.

The killing of Leonid Pliats and his boss on March 16 was captured on CCTV cameras in detail and is now being investigated by Ukrainian prosecutors as a potential war crime.

BBC says the footage shows five Russian soldiers wearing military uniform arriving in a stolen van daubed with the V sign. They fire at locks and smash glass.

Leonid, a 68-year-old security guard, is seen walking towards the soldiers with his hands up to show he is unarmed and no threat.

The Russians initially talk to him and his boss through the fence but the footage shows the Ukrainians to be calm. The men were hauled out into the street and frisked for weapons, before being asked for cigarettes.

There seems to be some conversation before the soldiers turn away and the two civilians begin to walk back to their guard post.

Pliats managed to walk back to the post to ask for help before he died.

Suddenly they turn back, crouch, and then shoot the two men multiple times in their backs.

The soldiers are then filmed ransacking the businesses, unaware that Pliats was still alive on the ground.

The video then shows Pliats struggle to his feet, and hobble back to his guard post. There, he gets a phone to call for help, CNN reports. 

The footage shows Pliats slumped inside the guard hut as the Ukrainians eventually arrive to help. They drag him out, leaving a wide swath of blood but he dies outside the guard shack.

The victim's daughter, Yulia, told CNN she could not bear to watch the video of the day her father died, but she is saving it to one day show her children, so they don't forget how savage the invaders were.