UPDATE 4:40PM SH5 is now OPEN to one lane under STOP/GO traffic management, following a serious crash in Rangitaiki. Please take extra care and prepare to stop on request. ^EHhttps://t.co/RvP3CPjGHl
Motorists should avoid the area or expect significant delays, a police spokeswoman said.
A Hawke's Bay DHB spokeswoman confirmed that two people were airlifted to Hawke's Bay Hospital in critical condition. Both were woman, one in her 20s and another in her 50s.
The spokeswoman said they were potentially expecting more injured coming in from the scene.
A St John spokesman said earlier that two helicopters and two ambulances were at the scene.
A woman at the nearby hotel said a witness to the crash described it as a "head-on".
The woman said it appeared a car had drifted across the centre line into another vehicle, which was then hit by an oncoming truck.
The person who called emergency services was "definitely shaken up".
"The car was right in front of them. It just veered across the centre line."
UPDATE 2:15PM Due to a serious crash near the intersection with Matea Road, SH5 in Rangitaiki is CLOSED. Please consider to use Palmerston North and Gisborne as alternative routes. Please plan ahead and delay your journey, if possible. ^EHhttps://t.co/RvP3CPjGHl
The woman said it was a sad start to Christmas for all of those involved.
A Rangitaiki Tavern worker said occupants from a car who witnessed the crash rushed to their pub to use the phone to call emergency services.
The crash happened near the tavern and there was no mobile phone reception out there, she said.
The eyewitnesses had come in looking frantic, she said.
SH5 RANGITAIKI, BAY OF PLENTY - SERIOUS CRASH - 1:45PM We have reports of a serious crash near the intersection with Matea Road. Please follow directions of emergency services on-site. An update will be provided as soon as more information is available. ^EH pic.twitter.com/JJEdhr9z4I