The police Serious Crash Unit is looking into the cause of the crash.
A person suffered critical injuries and another four people were taken to hospital after a five-car crash at Flat Bush, South Auckland.
The collision happened at 8.30pm at the intersection of Te Irirangi Dr and Ormiston Rd.
Five patients were taken to Middlemore Hospital, an ambulance spokeswoman said.
"One person was in a critical condition, three had moderate injuries and another had minor injuries."
The intersection was closed for about two hours while the Serious Crash Unit investigated.
Meanwhile, in Mt Roskill a person was seriously hurt after the car they were in struck a pole.
The incident happened about 8.35pm on Mt Albert Rd and the injured person was taken to Auckland City Hospital.
One person had to be freed from a car that had hit a power pole in Mangere Bridge just after 2.30am.
A police spokeswoman said the crash happened on the corner of Wallace and Creamery roads and two people were taken to Middlemore Hospital, one in a serious condition and the other with moderate injuries.
Just before 4am in Auckland, one person was pulled out of a car that had reportedly flipped on Gillies Ave.
St John ambulance took the person, who was in a moderate condition, to Auckland City Hospital and police are investigating the cause of the crash.
In Hamilton East, one person had to be freed from a car that had crashed into a pole at 4.30am.
Two people were taken to Waikato Hospital by ambulance, including one in a serious condition.
Traffic control was in place at the scene on Naylor St for about an hour as emergency services cleared debris from the road.
