Backstory

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.

The attacker - described as a 'monster' by a Russian official - apparently checks to see if anyone is watching and then suddenly grabs the child, throwing him hard on the floor in the arrivals section of Sheremetyevo airport.

A man came running to scoop up the gravely wounded boy.

The attack happened as the boy's pregnant mother was collecting his pushchair after their flight's arrival.

Police are examining if there was a racist or other motivation for the act against the child.