Police say a Thames-Coromandel District road is expected to be closed for at least six hours after a serious crash involving a truck and car in Whenuakite.

Police said they were called to the two-vehicle crash on Whenuakite River Bridge about 2.20pm.

Serious injuries were reported and the Serious Crash Unit has been advised.

Hot Water Beach Rd is closed for the emergency response and investigation.

Motorists are advised to take alternative routes and expect delays.