Five people were injured in a collision involving four vehicles on Ingestre St between Harrison St and Somme Pde in Whanganui.
A St John Ambulance spokeswoman said of the five people injured in Friday's accident, four had moderate injuries and one was in a serious condition.
"Four people were transported to Whanganui Hospital and one was treated at the scene," she said.
A police spokeswoman said officers were called to the accident shortly after 7pm and traffic was diverted for around two hours.
"Police responded to a collision involving a van and three cars on Ingestre St," she said.