Perth, Australia - Emergency services were Wednesday assessing the damage after the most powerful cyclone ever recorded in Australia pounded its north-west coast.

Cyclone John thundered over the coast near the tiny community of Whim Creek, bringing wind gusts up to 300km an hour, but officials believe bigger coastal towns managed to escape its full fury.

It was described by the Bureau of Meteorology as a top-rating category five cyclone, stronger than Tracy that devastated Darwin in 1974 or Vance that destroyed much of Exmouth, Western Australia, earlier this year.

A State Emergency Services (SES) spokesperson said no major damage had been reported in the bigger towns of Karratha and Port Hedland, but SES crews had been unable to get a clear picture because residents were unable to leave their homes.

No reports had been received from Whim Creek, where local residents were reported to have sought refuge inside a shipping container.

An SES spokesperson said the neighbouring community of Point Samson was believed to have suffered some damage, the extent of which was not yet known because telephone lines were down. About 500 Point Samson had been evacuated to shelters in Wickham.

"We won't know how bad the damage is in those places until we can establish contact with them, and we're not sure when that will be," the spokesperson said.

"At this stage we think there's probably been only light damage," she added.

Houses had lost their roofs and trees had been uprooted, but no casualties were reported.

Bureau of Meteorology cyclone forecaster Brian Bowase said John was "unequivocally" the most powerful cyclone ever recorded in Australia.

"Had this one come across the coast at Karratha, we would have been looking at a similar thing to Tracy in terms of destruction," he said. "It's just lucky it's crossed at Whim Creek, which is a one-pub town."

However, Bowase warned that a second tropical cyclone, Ilsa, was following in the wake of John and could cross Western Australia's coast on Thursday.

Ilsa was expected to be upgraded from a category one cyclone as it approached the coast between Broome and Exmouth. -