The slow-moving cyclone was at the highest category of five as it landed east of Port Hedland -- one of the world's busiest iron ore ports -- said the Australian Bureau of Meteorology.

The storm packed "very destructive" wind gusts of 290 kph (180 mph) as it dumped intense rain and threatened flash floods and storm surges, said the bureau's Matthew Collopy.

But the eye of the cyclone passed east of Port Hedland, sparing it from the fiercest winds and "greatly" reducing the risk of a storm surge in that area, he said.

The cyclone weakened slightly to a category four as it moved over the Pilbara region.

People in Port Hedland --- about 17 hours' drive north of state capital Perth -- queued for sandbags as the cyclone approached, while others huddled inside.

Resident Bianca Katai said she had experienced category five cyclones in the area before.

"This one is still pretty breathtaking, just the raw power that comes with it. There is a lot of wind and rain, and you don't realise until you are in it," she told AFP.

Katai said she ventured outside before taking safety in her home.

"Most trees toppled over but it hasn't flooded. All the trees fell sideways, but the roads are pretty clear," she said.

- Iron ore ports closed -

Emergency services in Western Australia told people in the cyclone's path to shelter in the strongest part of their homes, warning it was too late to attempt to leave.

Forecasters said the cyclone was now expected to track inland across sparsely populated mining and cattle country.

The northwest coast of Western Australia is the most cyclone-prone region in the country, according to the Bureau of Meteorology.

The last category five storm to cross into Western Australia was Cyclone Ilsa in April 2023.

The Pilbara region holds significant deposits of iron ore, copper and gold, and is home to some of Australia's largest mining operations.

Pilbara Ports said it had cleared vessels and shut down operations at major minerals export centres Port Hedland and Port Dampier as well as the oil and gas shipping port of Varanus Island in preparation for the latest storm.

Mining group Rio Tinto cleared ships from ports in the area and stopped rail transport.

"It is too early to say how long port and rail operations will be closed and what the impact will be," it said in a statement Thursday.

Mining firm BHP "paused" its operations in Port Hedland and said the city airport had cancelled all flights in and out.