"Four children were injured," van der Merwe said.
"They are reported to have received puncture wounds to their legs, arms and backside. Two of the children had their wounds dressed by paramedics on site and two were taken to hospital for further treatment."
The dogs, which are registered, reportedly ran off down Mt Albert Rd, but have since been found after a search by four animal management officers, police and the dogs' owner.
The dogs are now impounded, van der Merwe said.
"We have notified the school that it is now safe for the children to be released. Our
investigation is ongoing."
A St John spokesman said two ambulances attended the scene.
School principal Jo Willmoth told Fairfax the dogs ran on to the school field at lunchtime, chasing children and nipping some.
She said the school went into lockdown when the dogs were on the loose and parents were emailed about the situation.