A man has been shot dead by police after coming at them with a weapon on State Highway 1 near Pohuehue north of Auckland early this morning.
And both police and the New Zealand Transport Agency have warned motorists to expect delays as Easter weekend traffic coincides with the continued closure of SH1 between Woodcocks Rd, in Warkworth, and Silverdale.
The 27km section of highway has been closed since 4am, after a 29-year-old died in the shooting near Pohuehue, north of Puhoi.
Police said the road was expected to remain closed for much of today as officers worked at the scene of the shooting.
There is also a no-fly zone in place.
Motorists should delay travel, where possible, or take diversions via SH16, the only north-south option.
There is no indication of when the cordon at Puhoi might be lifted, but the Herald understands it will be at least several hours as the body is still inside the cordon.
A Herald reporter said traffic before Silverdale was backing up suddenly before the cordon diverting people to SH16 through Orewa. She was in the area about 9.45am.
"It's otherwise free flowing northbound."
A Herald photographer said the Hibiscus Coast Highway at Hatfields Beach was also cordoned off.
Earlier, in a statement, police said the 29-year-old man was shot after he approached officers with a weapon.
First aid was given, but he died.
The exact circumstances of what occurred remain unknown, but Radio New Zealand reported a motorist saw road spikes just before the offramp at Silverdale about 4.30am.
Police were stopping vehicles and letting them through one-by-one, the man told the state broadcaster.
A police spokeswoman said further information would be provided to media by Waitemata District Commander, Superintendent Tusha Penny, at 1pm.
Residents within the road closure area told the Herald they'd heard helicopters early this morning, but were not aware of the man's death.
Glen Foote, who lives on Woodcocks Rd about 1km from Warkworth, heard helicopters doing tight circles, followed by multiple sirens at 4am. The noise was coming from the west.
"It sounded like they were chasing somebody."
Warkworth resident Becky Watson said she also heard helicopters in the area at 4am.
"[They were] flying so low it woke me up."
Auckland Transport operations centre manager Rua Pani said there was no north-south access via the Hibiscus Coast Highway or east coast roads.
"Motorists are advised to leave SH1 at Silverdale or Warkworth to get on to SH16. Motorists will be able to continue on SH1 north to reach the beachside communities at Orewa and Whangaparaoa and south to reach Warkworth, but there will be no through traffic."
Historical data for Easter holiday travel suggests traffic heading north will get heavy from 10am and be very heavy from midday.
"State Highway 16 is not designed for that volume of traffic so there will be congestion and delays."
The following diversions are in place:
SH1 Northbound: Traffic is advised to exit at Silverdale, turn left onto Dairy Flat Highway, right onto Kahikatea Flat Rd, right on to SH16 and travel north to Wellsford.
Motorists can use West Coast Rd to Warkworth however there are narrow bridges on this route. SH1 will remain open at Silverdale to allow access to Silverdale and Whangaparaoa however the SH1 is closed at Orewa.
SH1 Southbound: Traffic is advised to exit SH1 at SH16 Wellsford, head south to Kahikatea Flat Rd back to Silverdale or carry on south to the SH16 North Western motorway.
SH1 southbound is closed at Woodcocks Rd in Warkworth detour to SH16 via West Coast Rd.
It's been a grim start to the Easter Holiday, with three major crashes in the North Island yesterday.
A child was killed after a crash on the Desert Rd in Waikato about 3.30pm Friday. One person remains in Waikato Hospital's High Dependency Unit and another has been transported to Auckland's Starship Hospital.
One person died following a crash in southern Bay of Plenty between Pokuru Rd and Tirohanga Rd at 10.52am.
A crash Friday morning south of Matamata on SH27 and SH29 has also left one female adult in a critical condition at Waikato hospital.
Three children were involved in the accident but are in a stable condition.