SYDNEY - Australia's iron ore export hub, the world's largest, braced on Friday for a powerful tropical cyclone, forcing the closure of all of the major commodity ports in the country's northwest as residents rushed to stock up on essential supplies.

Cyclone Zelia, located in the Indian Ocean about 80 km north of Port Hedland, has been upgraded to a category five storm, the highest rating on the scale, Australia's weather bureau said in its latest warning note.

The system is expected to make landfall on Friday evening near Port Hedland in the Pilbara region, packing wind gusts of up to 320 kph and bringing heavy rains across a 550 km sparsely populated stretch, the weather bureau said.

ALSO READ: Tropical cyclone forces closure of ports in Western Australia's Pilbara region

"We haven't seen the worst of the weather yet but we've already started to see the rainfall numbers tick up and some strong wind gusts along the coast," forecaster Angus Hines said.

Port Hedland's port, the world's biggest iron ore export point, was closed on Wednesday, while the ports of Dampier and Varanus Island, a gathering and processing hub for oil and gas, were shut down on Thursday evening. Cape Lambert was also shut.

Port Hedland is used by BHP Group, Fortescue and billionaire Gina Rinehart's Hancock Prospecting, while the Dampier and Cape Lambert ports ship iron ore from Rio Tinto.

BHP and Fortescue said separately that their Port Hedland operations had been paused for safety and that teams had been instructed to shelter at home or at camp. Fortescue said it had also closed its Iron Bridge mining operations and canceled non-essential travel to Pilbara sites.

Rio said it had cleared its Cape Lambert and Dampier port operations and there were no longer any ships or trains operating at its ports, and reiterated an earlier statement that its first-quarter shipments would be affected by weather events.

"The company is working to mitigate impacts and will provide operational updates as appropriate," Rio said in a statement.

All three of Australia's iron ore miners are scheduled to report financial results next week.

The potential disruptions to supply from Western Australia did not impact Dalian iron ore futures on Thursday, which snapped a two-day rise amid concerns over the US steel tariffs and potential Indian taxes.

Iron ore is the primary raw material used to make steel.

Port Hedland's 15,000 residents, most of whom are mining company employees, have been advised to seek shelter indoors, while non-essential staff have been moved to safe locations.

Some supermarkets have been closed, ABC News reported, after essential supplies ran out as people stocked up.

In April 2023, Cyclone Ilsa hit the Pilbara region as a category five storm setting new wind speed records but largely spared populated regions, including Port Hedland.