Emergency services are responding to a crash on Atawhai Drive in Nelson.
The crash, involving a car and van, occurred at around 4.25pm.
The three occupants of the car have been injured, with one person reportedly suffering critical injuries, one serious and one moderate.
Two people in the van are reported to have moderate injuries.
Motorists are asked to avoid Atawhai Drive between Allisdair Street and Wakapuaka Road while emergency services work at the scene.