Stomach-churning footage shows a gang of 10 thugs battering the youngster in Bradford after throwing him off his bike.
The sickening clip, filmed by a passerby, opens midway through the one-sided punch-up and shows the boy being dragged out to a water feature.
He is then stamped on his head several times – all while an adult with a walkie talkie and blue vest simply looks on.
Astonishingly several other onlookers also stand around in shock and fail to intervene as the boy suffers the brutal assault.
The video appeared on Twitter yesterday and has since accumulated more than 52,000 views.
The post was captioned: “Bradford.”
Towards the end of the video the man with the walkie talkie appears to finally intervene and urges the thugs to stop.
But one yob then proceeds to kick the lad in the head while he whole body slumps in the water feature.
The victim then tries to push himself off the ground when the video stops.
A spokesman for West Yorkshire Police said the force is aware of the incident.
He said: “Police are making enquiries into this footage to establish when this incident occurred and to identify those involved.”