Emergency services are at a two-vehicle crash on State Highway 2 near Ōtāne in Central Hawke's Bay.
One person is reported to have been seriously injured and a rescue helicopter is in attendance.
The two vehicle crash was reported to police at 3.50pm.
Motorists are asked to take alternative routes where possible, or delay travel, as only one lane is open.
An update will be provided when more information is available.