POLICE are gathering mobile footage of a sickening schoolyard fight in which a Year 7 student is viciously punched and knocked off his feet by a 14-year-old boy.

The NSW Education Department, together with the police, have launched an investigation into the brutal incident which is said to have taken place at a high school in Wagga Wagga in the the state's Riverina.

In footage aired on Channel 7 last night, the boy is seen rocking on his legs before falling slowly face-first to the ground after being punched with such force he can't keep standing.

Seven said the 12-year-old lay unconscious on the pavement with no help in sight - just amateur cameramen.

The incident, filmed on Monday, has been seen by the Education Department which said "the school responded immediately and appropriately" to the incident.

"Wagga Wagga High and other NSW public schools do not accept violence, bullying or other forms of inappropriate behaviour," according to a statement.

"The school is investigating and disciplining those who condoned the irresponsible action by recording and distributing vision of the unacceptable behaviour."

Police are undertsood to be interviewing the victim and no charges have been laid at this stage over the incident.

They are also in the process of collecting more video footage of the attack and will question anyone who filmed it.