A vehicle involved in a serious crash involving young children was stolen, police have confirmed. 

Five young children were seriously injured after they were flung from the vehicle in a crash near Matamata. 

Arriving at the scene about 11.55pm yesterday, police found the Nissan Tiida in a ditch on Morrinsville-Walton Rd with the five children – aged 10 to 13 – outside the car. 

All five were taken to Waikato Hospital - four by ambulance and one by rescue helicopter. 

Police confirmed the vehicle involved in Monday's serious crash had been stolen from Hamilton. 

Inquiries also suggest the vehicle was linked to a burglary on Monday evening in Matamata. 

Waikato District Commander Superintendent Bruce Bird said information is being assessed by staff investigating this crash. 

"It is too early to provide detail on the cause of the crash itself other than to say speed appears to be a likely factor," he said. 

Police are not looking to locate anybody else in relation to the crash. 

Four children remain in a critical condition in Waikato Hospital's Intensive Care Unit. One child is expected to be transferred to Starship children's hospital later today. 

A fifth child remains stable in Waikato Hospital. 

"While we understand there may be speculation about what occurred, it's important police have the opportunity to investigate the circumstances, and the families impacted are given the space to support their children," Bird said earlier today. 

"They acted quickly and professionally in difficult conditions to ensure these young people got the medical attention they urgently needed." 

The crash site, while initially closed to traffic, had since reopened.