AUSTRALIA – Australian Prime Minister Malcolm Turnbull has activated a disaster response plan after a powerful cyclone pummelled the north of Queensland.

Cyclone Debbie caused major damage, torrential rain and power cuts to tens of thousands of homes.

Defence force helicopters and naval vessels carrying aid are to be despatched to Queensland.

More than 45,000 homes are without power throughout the impact zone and authorities have warned they will not be able to render assistance until Wednesday at the earliest.

The Insurance Council of Queensland has already declared the storm a “catastrophe”.

The scale of destruction from the category four storm was yet to emerge on Tuesday evening amid reports of severe damage to homes and communities cut off from communications.

The destructive core of the cyclone hit the coast near Airlie Beach about midday local time after wreaking havoc on the Whitsunday tourist islands, where winds blew up to 265kph and ripped roofs off houses.

There were fears of major damage on the mainland at Proserpine and police warned there could be casualties from the slow-moving cyclone.

Fears of damage from a storm surge in Mackay at the southern edge of the impact zone faded as Debbie was downgraded to a category-three storm about 4.00pm.

But the Queensland government, after days of preparations including forced evacuations of some areas, remains on a disaster footing, with weather experts warning that the cyclone could take until Wednesday to dissipate.

The state’s premier and police commissioner both issued warnings. “We are going to get lots of reports of damage and sadly I think we will also receive more reports of injuries, if not deaths,” said the commissioner, Ian Stewart. “We need to be prepared for that.”

“We’re going to see the impact of Cyclone Debbie for the next three to five days as it travels down the coast.”

He said authorities were bracing for the full picture of injuries to emerge from communities that had been cut off from communications.

In Bowen, where much of the local housing was built before cyclone safety standards were introduced in the 1980s, the cyclone wrecked homes and caused “major environmental damage”, Whitsunday regional councillor Mike Brunker said.

With dangerous winds and rain set to keep Bowen residents indoors well into Tuesday evening, the scale of devastation would not be clear until Wednesday but “there will be some considerable amount of damage,” Brunker said.

Tony Fontes, a dive tourism operator who sheltered from the cyclone at his Airlie Beach home 500 metres from the ocean, said the experience had been “bloody scary”.

“Lots of large tree branches crashing on the house roof and steadily rising water,” he said.

Fontes said he expected Cyclone Debbie would be a mixed development for the Great Barrier Reef. Local coral would be damaged but the stir of water would cool sea-surface temperatures now causing mass bleaching across the broader reef.

“We’ve seen cyclone damage to the reef before and it is awful,” he said. “Locally it’s a disaster but reef-wide it’s a good thing – I guess that’s the best way to look at it.”

A Bureau of Meteorology spokesman said Mackay, the most populated area at the southern edge of the cyclone watch zone, had missed out on a disastrous storm surge “by a whisker”

The storm’s later than expected arrival meant the inundation did not add to a high tide, but heavy rain was expected to continue across the region.

On Monday authorities urged 25,000 people to evacuate low-lying areas of the city but it was not clear how many followed that advice.

- PNC sources