State Highway 25 is closed through Thames following a serious crash involving a motorcycle.
One person was in critical condition, police said.
Northbound traffic on SH25 was being turned back at Kopu and southbound traffic was being turned back at the north end of Thames.
The crash, happened along the highway near Banks Street, and was reported at 11.55am.
Police said the road was expected to be closed for several hours.
“Motorists are advised to avoid the area and expect delays.”