Police are in attendance at a serious crash on a section of State Highway 1, just south of Warkworth.

The crash, involving two vehicles, was reported at 1.38pm. One person is in a critical condition and will be transported to hospital. 

A section of State Highway 1, south of the Warkworth township, is currently closed and diversions will be put in place for traffic heading north and south.

The Serious Crash Unit has been notified and will be examining the scene. 

Police are advising motorists to plan ahead and expect delays on their journeys this afternoon. 

UPDATE 3:40PM - One person is reportedly dead with four others injured. The crash was near Cowan Bay Road. Road is currently closed.