Two people have been seriously injured in a multi-vehicle crash in Whangārei on Thursday morning.

Emergency services responded to crash on Pipiwai Rd in Ngararatunua at about 8.32am.

Two people were taken to hospital and are in a critical condition. Another person has moderate injuries, police said.

The Serious Crash Unit is in attendance.

A section of the road, which is more than 13 km long, is likely to be closed for some time while the scene is cleared.

Police are warning drivers to expect delays and take alternative routes if possible.