Appalling footage shows the moment a male tourist suddenly picks up and hurls a helpless 18-month-old boy head first on the ground in the arrivals hall of a Moscow airport.

The boy is now fighting for his life in a coma with serious skull fractures and spinal injuries.

The child had arrived in Russia after he and his mother fled the bombing in Iran, say reports.

The tourist - identified as Vladimir Vitkov, 31, from Belarus - is seen on security footage looking closely at the boy who is next to his suitcase.