World Bulletin / News Desk

Torrential rain hampered relief efforts Thursday after a powerful cyclone wreaked havoc in northeast Australia, with floods sparking emergency rescues as fed-up tourists began evacuating from resort islands.

It has been downgraded to a tropical low as it tracks southeast, but continues to pack damaging gusts and dump huge amounts of rain, with Brisbane now in the firing line.

Meteorologists said the city was soaked by a month's worth of rain in a single day, with the popular Sunshine Coast and Gold Coast areas also drenched ahead of the system moving offshore, expected Friday. 

Theme parks and beaches in the area were closed.

"We have a very, very large state here and this is a very, very big weather system that's going to wreak havoc all the way down the coast," Queensland Premier Annastacia Palaszczuk said.

Emergency service crews, who took more than 3,000 calls for help, rescued dozens of people from floodwaters, with some plucked from roofs and tops of cars.

To reinforce the message that people should steer clear of floods, Queensland Fire and Emergency tweeted a picture of a shark washed up on a road near the town of Ayr.

"Think it's safe to go back in the water? Think again! A bull shark washed up in Ayr. Stay out of floodwater," they said.

Despite the ferocity of the storm, no deaths have been reported with only one significant injury -- a man crushed by a collapsing wall. Before the cyclone hit, thousands of people moved to higher ground, out of the area or to safe refuges.

The wild weather has made the clean-up difficult as crews battle horrendous conditions to reach isolated communities and restore power. 

Many roads remain flooded and towns cut off with hundreds of schools closed and authorities keeping a close eye on dams as water levels rise.

Flood evacuation orders were also put in place for parts of northern New South Wales, which neighbours Queensland.