A woman was seriously injured when a truck and car collided in Manawatu this morning, forcing police to close a stretch of State Highway 57.

Emergency services were called to the crash near Ihakara, about 8km north of Levin, at about 7am.

The woman was cut from the car and taken to hospital with serious injuries, police said.

The highway was closed between Graham St and Tavistock Rd and police were this morning working to clear the crash site.