Four children in critical condition after being thrown from vehicle in Matamata, Waikato crash

Five children are injured, four critically and one seriously, after a horror crash in the Waikato town of Matamata.

Police say the five children, all aged between 10 and 13, were found outside of the crashed car on Morrinsville-Walton Rd just before midnight on Monday.

"All five were taken to Waikato Hospital - four by ambulance and one by helicopter," a police statement said.

"Four remain in the intensive care unit in a critical condition and another is in a ward in a stable condition."

An investigation into the crash is now underway.

"At this early stage our focus is on understanding what led to this very serious crash," Waikato District Commander Supt Bruce Bird said.

"Police would like to thank the members of the public who went to the children's aid immediately after the crash.

"I also want to acknowledge the emergency service staff who responded.

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

Bird said while there may be speculation about what happened, he urged the public to give police the opportunity to investigate the crash - and give impacted families space to support their children.