BHP Billiton said it had suspended all its iron ore rail operations in Western Australia on Monday after a train ran away at high speed for nearly 100km before being forcibly derailed.

No-one was injured and the train, loaded with iron ore, was travelling in a remote area. However, operations would be suspended while an investigation was under way, a spokesperson for BHP, the world’s biggest miner, confirmed.

The Australian newspaper had earlier reported that BHP had suspended rail operations in the region after the incident.

The train, which was running on BHP’s private Mount Newman railway line, took off while the driver, the only person on the train, had temporarily stepped off the locomotive to inspect an issue with a wagon.

The train ran for 92km at about 100km/h, Reuters calculations show.

The incident is likely to raise safety concerns about miners’ plans to bring driverless trains to Australia’s iron ore heartland. Rival Rio Tinto made its first iron ore delivery by autonomous train in July.

The Mount Newman railway line carries ore from Newman in Australia’s iron ore-rich Pilbara to Port Hedland across a remote 426km and is one of Australia’s longest private railways.

Australia’s transport authority said it was investigating the incident.

“A Western Australia iron ore train has been derailed near Turner River on route to Port Hedland,” BHP said in a statement. “No-one has been injured. We are working with the appropriate authorities to investigate the situation.”

The damage to the train was “substantial”, The Australian Transport Safety Bureau said in a report.

While the driver was outside of the locomotive, the train took off. “With no-one on board, the train travelled for 92km until ... the train was deliberately derailed at a set of points operated by the control centre, about 119km from Port Hedland,” the transport safety bureau said.