Traffic mayhem on Auckland's Northwestern Motorway after six-car nose-to-tail

Traffic is backed up for kilometres on Auckland's Northwestern motorway. Photo / File

One person is moderately injured after a six-car pile up on Auckland's Northwestern Motorway that caused traffic to back up for several kilometres.

The crash happened citybound between the St Lukes on-ramp, and the Newton Rd off-ramp, about 7.30pm.

A police spokesperson said it was thought six cars collided nose-to-tail and one person suffered moderate injuries as a result of the crash.

Motorists are being asked to delay their journey or to take another route.