A person has been critically injured in a crash in Northland believed to have involved a logging truck.

Police said the vehicle crashed on Mangakahia Rd in Tītoki around 12.20pm today.

A motorist turned around at the scene said they were told by police a logging truck had crashed into a bank.

Police said a section of Mangakahia Rd is currently closed and diversions are in place. Motorists are warned to expect delays while the scene is cleared.

The Serious Crash Unit has been called in to investigate.