Police are investigating the cause of two crashes on the same stretch of road in the Coromandel yesterday.

Emergency services were kept busy yesterday after two serious crashes in the space of a few hours in the Karangahake Gorge yesterday.

The Trustpower TECT rescue helicopter transporting a patient from the second crash yesterday afternoon. Photo: Supplied.

The first incident happened just after 10am on State Highway 2 left three people with critical injuries. The incident happen about 3km southeast of Te Moana.

The second incident happened just before 2pm about 5km east of Waikino, closing the same stretch of highway for several hours. The second crash was a head on between two cars saw three people trapped for a short time before being cut free by emergency services says a spokesman for the Northern Fire Communications Centre.

Two patients were airlifted to Waikato Hospital by the Auckland and Waikato Westpac helicopters and one, a 17-year-old Auckland woman, was airlifted by the Trustpower TECT rescue helicopter to Tauranga Hospital in a critical condition.

The Serious Crash Unit are investigating the two incidents. Police are asking motorist to drive to the conditions over the long weekend.