A 42-year-old man has been seriously injured in a truck crash on a mine site in Western Australia’s Pilbara.

Police say the man was injured when a dump truck ran into the back of another about 1:00 am at Christmas Creek mine, east of Nullagine.

The man was pinned in the rear truck’s cabin for more than five hours and suffered serious leg and pelvis injuries.

The Royal Flying Doctor Service flew the man to Royal Perth Hospital this morning where he remains in a critical condition.

The mine is one owned by Fortescue Metals Group.

The Department of Mines and Petroleum is investigating.