Two dead after horror Sydney Harbour Bridge crash

Officers found three cars and a bus had collided.

One man died at the scene. The second man was initially found in a critical condition and later died.

Then, a motorcyclist who allegedly rode through the crash scene was arrested.

He was taken to a local police station where he is assisting officers with their inquiries.

Police had to restrain a motor cyclist who allegedly breached a road block at the crash scene. (Dan Himbrechts/AAP PHOTOS)

The bus driver, who was driving an empty vehicle, was uninjured.

Paramedics were also checking other people for injuries.

Drivers have been urged to avoid the area after the bridge was closed in both directions.