Seven people are in hospital following a crash involving two vehicles in the North Waikato on Friday.

It came less than an hour after a serious crash in the Eastern Bay of Plenty, which saw five children injured.

A Bay of Plenty man was critically injured in a crash west of Opotiki yesterday. Photo: Trustpower TECT Rescue Helicopter.

And in the Coromandel, a campervan has been involved in a two-vehicle crash north of Thames, blocking State Highway 25. Emergency services are still at the scene of a crash involving a campervan and car north of Thames.

One person is trapped inside the car. The crash, which occurred at 5.20pm, blocked SH25 for a period of time.

The North Waikato crash happened at 2.30pm on State Highway 2, near Bombay, blocking the road from the SH1 turnoff at Pokeno to Mangatawhiri.

All seven patients were transported to Middlemore Hospital; four were in a serious condition, two suffered moderate injuries and one suffered minor injuries.

Senior Sergeant Andrew O'Reilly says there were a number of driving complaints and travellers need to be patient.

'Restraint and patience and drive to the conditions, especially with the incoming weather.”

In the Eastern Bay of Plenty, a head-on vehicle collision left one adult trapped and five with injuries.

The crash blocked the main road west of Opotiki. Read more here.

Tauranga-based Trustpower TECT Rescue Helicopter transported a critically injured man to hospital. Read more here.

The crash happened on State Highway 2 at 1.50pm at Waiotahi, 14 kilometres west of Opotiki.

Northern Fire Communication shift manager Megan Ruru says the children suffered moderate injuries.

"There were a total of nine people involved in the crash.”

The Police Serious Crash unit will investigate.