BHP says one of its iron trains derailed recently, but no one was injured.

A company spokesperson has revealed that a number of cars came off the Pilbara rail line at 6am last Wednesday morning, 67 kilometres south of Port Hedland.

BHP expects expected to re-open the line within days, and will report any loss of production in its quarterly operational review in December.

BHP said the incident did not affect loading or shipping, due to existing stockpiles at Port Hedland.

The Australian Transport Safety Bureau has undertaken an “office based” investigation.