Motorcyclist dies in crash north of Sydney

A 31-year-old motorcyclist has died in a crash on the Pacific Highway north of Sydney.

At least five Defence Force members have been seriously injured in a bus crash in southern NSW. (AAP)

A motorcyclist has died after crashing into a rock wall north of Sydney.

The 31-year-old man crashed just south of the Brooklyn turn-off on the Pacific Highway just before 4pm and was pronounced dead at the scene.

The Pacific Highway has been closed in both directions.