High winds are playing havoc with roads in northern Southland.

State Highway 97 (Mossburn to Five Rivers) is closed until further notice because of the strong winds.

Please avoid the area or delay your journey.

A truck and trailer unit blew over on State Highway 97 near Hillas Road.

The road is now clear but the threat remains.

The highway is closed, including Lowther Road and Ellis Road.

High-sided vehicles are warned to exercise extreme caution in the northern Southland area.

Meanwhile, Wreys Bush Mossburn Road is closed between Cemetery Road and Chewings Road after large trees were blown across the road.

Contractors are on site but it will take time to clear the trees.

We have also had reports of trees blown down across Wairio Wreys Bush Road.

Drivers are advised to drive to the conditions, exercise extreme care and be wary of trees and debris across the roads.