Two people are in Waikato Hospital in serious condition following a motorbike crash in the Bay of Plenty.

The Waikato Westpac Rescue Helicopter and the TECT Rescue Helicopter were dispatched to State Highway 5 on the Mamaku Ranges on Saturday at 11.40am.

'Within 25 minutes both helicopters were on the scene,” says a spokesperson for the rescue helicopters.

'The rider and passenger suffered serious injuries requiring transport to hospital.

'The TECT Rescue Helicopter transported a male in his 50's to Waikato Hospital and the Waikato Westpac Rescue Helicopter transported a female in her 50's to Waikato Hospital.”

The road was closed for several hours, and re-opened around 1.20pm.