Emergency services are responding to reports of a serious crash on State Highway 94 near Deer Flat, between Milford and Te Anau.

The crash was reported to Police at 11.55am.

Initial Information from the scene is that a van has rolled and several people have been injured.

Police advise the road is blocked in both directions and is expected to remain so for some time.

There is already significant traffic backed up on either side of the crash scene, they said.

No detours are available.

Motorists planning to travel between Milford and Te Anau are advised to delay travel.