MACKAY, Australia (AFP) - Australian officials on Sunday said all efforts were being made to help those affected by Tropical Cyclone Marcia, which smashed through Queensland state, leaving 1,500 homes damaged and thousands without electricity.

Marcia was one of two fierce cyclones that hit northern Australia within hours on Friday, with the first being Tropical Cyclone Lam, which hit remote communities in the Northern Territory near Elcho Island, some 500km east of Darwin.

Marcia, a maximum category-five storm, tore through eastern Queensland, badly affecting Yeppoon, about 670km north of the capital Brisbane, before heading south to Rockhampton. "We've had assessments of over 1,500 houses that have had some kind of structural damage," Queensland Premier Annastacia Palaszczuk said. "In Yeppoon and Rockhampton around 100 are severely impacted... people can't go back into their homes. Our fundamental priority now is on those families who have been the most severely impacted."

As the clean-up gathered pace, electricity and telephone companies were working to restore power and communications. "There are over 1,800 (power) lines down. This is absolutely significant, and we are doing everything we possible can to restore power," Ms Palaszczuk said.

The government has committed army reservists to help with the clean up in Yeppoon, as well as disaster relief funding to those affected in Queensland.

"The power of the cyclone is evident everywhere, the destruction of the vegetation is extraordinary, obviously a lot of buildings have been severely damaged," Deputy Prime Minister Warren Truss said as he toured the state.

In the central Queensland town of Biloela, about 100km south of Yeppoon, several hundred homes are believed to have been inundated by flooding brought by the storm.

Despite the destruction, the authorities have so far not received reports of serious injuries or deaths but residents have spoken of the terror of the storm.

"You could see the neighbours' roofs flying across the paddock," said Ms Karen Johnston, who was in her home in Marmor, some 45km south of Rockhampton, as the cyclone passed.

"And the horses were running around the paddock and all I could think was, 'We are going to have a horse decapitated or sliced in half'," she told the Australian Broadcasting Corporation.

The Bureau of Meteorology cancelled its severe weather warning for Queensland on Sunday, saying former tropical cyclone Marcia had now travelled offshore and was expected to remain there.

But flood warnings were in place for parts of the state's south-east, although the Mary River has peaked in the town of Gympie south of Rockhampton and is expected to recede.

Queensland has been smashed by several major storms and cyclones over the past few years with Cyclone Oswald, also a category five, flooding parts of the state in 2013, racking up insurance claims of some A$977 million (S$1.04 billion).

In the Northern Territory, a state of emergency has been declared for the areas worst-hit by Cyclone Lam, with trees ripped up and some homes destroyed.

Northern Territory Chief Minister Adam Giles told Elcho Island residents that the government would do all it can to help.

"I was expecting people to be much more devastated, but people are in very good spirits," he said.

"It's heartbreaking for anyone to come and see."