Police say that a 20-year-old Thebarton man was seriously injured when his motorcycle crashed on Main North Road near Clifton Street, Blair Athol at 5pm on Saturday.

He was taken to the Royal Adelaide Hospital but died on Tuesday.

Police and emergency services were called to another motorcycle accident at 6pm on Tuesday after reports a Harley-Davidson and a station wagon had collided on Seaview Rd at Henley Beach.

The motorcyclist then hit a parked car and tree. The 25-year-old Seaton man died at the scene.

The deaths take the state’s road toll to 87 compared with 55 at the same time last year.