Four people are injured and part of State Highway 1 was closed following a crash north of Auckland.
The crash in Dome Valley, close to where SH1 meets Waiwhiu Conical Peak Rd, was reported just after 11:30am on Wednesday morning.
Police say it involved two cars and left one of the four victims critically injured. Two others are in a serious condition and the fourth has moderate injuries, a St John spokesperson told Newshub.
Three rescue helicopters attended the crash to treat the injured and transport them to hospital - two from Auckland, and the other from Northland.
Two ambulance crews were also at the scene, along with police.
A call was earlier made to close the section of SH1 between Warkworth and Wellsford until the crash was cleared.
The road was blocked for several hours, and police set up diversions on SH1 at Kaipara Flats Rd to the south, and at Wayby Valley Rd to the north.
A detour was set along State Highway 16, West Coast Rd and Woodcocks Rd, meaning the normal 20-minute journey between Warkworth and Wellsford took close to an hour for some motorists.
Police had advised drivers to avoid the area and expect delays, with diversions expected to remain in place for some time.
However just before 3:30pm, the New Zealand Transport Agency (NZTA) announced SH1 had reopened.
The Serious Crash Unit has been advised of the incident.