State Highway 2 is closed at Whakamarama following a crash between a car and van, and two people have been taken to Tauranga Hospital with serious injuries.
Police were called to the crash at 3.30pm and another person was also taken to hospital with moderate injuries.
The road was closed near the Munro Rd intersection and traffic diversions were in place.
There is debris and fluid on the road which is expected to take a few hours to clean up, police said in an emailed statement.
The Serious Crash Unit is in attendance.
A local resident, who did not want to be named, told the Bay of Plenty Times she heard tyres screeching and waited for the sound of a collision.
Running outside, she saw two cars and people running towards them.
"Someone called for a fire extinguisher. We got ours ... and sprayed the one car. The two people in the white van were both unconscious.
"Luckily there was a trained medic on hand and talked everyone through what to do."
The woman said she then got some pillows and umbrellas to help keep the three people comfortable and tried to assist until the Fire Service and ambulances arrived about 10 minutes later.
Traffic is heavy and the New Zealand Transport Agency is advising people to avoid the area or use an alternative route.
Motorists are warned to expect delays and avoid the area if at all possible.
Anyone who witnessed the crash is urged to call Tauranga Police on (07) 577 4300 or call the Crimestoppers line anonymously on 0800 555 111.
David Seymour’s Treaty Principles Bill was introduced to Parliament on Thursday.