A section of State Highway 1 at Piarere has reopened following a serious crash.

Emergency services were alerted to the crash about 5.30am.

In a statement this afternoon, a police spokesperson said three people suffered serious injuries and two people were critically injured. 

A witness on the scene moments after the crash, who would not be named, said both vehicles looked badly damaged.

“They were both pretty banged up, I could see the crash was still really fresh when we arrived, it had only just happened.”

The woman said she saw emergency services moving back and forth working to extract people from the vehicles.

“I saw the two cars facing towards each other and people still in them,” she said.

Hato Hone St John said five people have been taken to Waikato hospital with serious injuries.

They responded with five ambulances and two rapid response vehicles.

The road was closed for several hours and reopened about 11.30am.