This is the horrific moment when a jet ski kills one victim and injures another when it smashes into an inflatable on a Russian river.

The victims were being towed on a doughnut ring by a motor boat on the Irtysh River in Omsk.

But as the pair laughed and shouted as they were bucked around in the waves, a jet ski rammed into them at high speed.

Graphic footage of the smash – filmed from the motor boat – shows one 22-year-old rider being hit so hard he is sent flying through the air.

The other – more shielded from the impact – survived but was injured in the collision, report local media.

Police say the jet ski pilot fled instantly and has not yet been traced.

The Eastern Interregional Investigation Department for Transport of the Investigative Committee of the Russian Federation has opened an investigation into the incident.

At the time of reporting, investigators had already studied the crime scene, seized the motor boat and doughnut ring, and interviewed the boat pilot and witnesses.