The Parapara Rd, part of State Highway 4 between Whanganui and Raetihi, has been closed due to the surface being unstable near Ohotu Rd.

The NZ Transport Agency reports that contractors have advised them it will remain closed until Thursday, with an update expected in the morning.

Road users are advised to use State Highway 1 as a detour route and to allow extra time for their journeys.

Residents will still have access to their homes.