A man was killed when the high-powered motorcycle he was riding crashed at Dairy Flat, north of Auckland, early on Sunday morning.
Police say the 52-year-old was thrown from the bike when it failed to take a corner, and he died at the scene.
A 52-year-old male pillion rider was taken to Auckland Hospital, where he is in a serious condition with multiple leg fractures.
In Tauranga, police say a 21-year-old man and an 18-year-old woman are in hospital with serious injuries after a crash on a rural Maketu road on Saturday night.
They say they believe that speed and alcohol were factors in the accident.