Cyclone Alfred was downgraded to a tropical low on Saturday but is due to make landfall near the Queensland capital city of Brisbane soon.

Officials have warned residents to stay indoors and remain vigilant, saying the storm's threat is "not over". Winds have brought down trees and power lines and flooded low-lying roads. More than 300,000 properties are without power in the region.

Police said Saturday they had discovered a body in the search for a 61-year-old man who went missing on Friday after his car was caught in floodwaters in Dorrigo, northern New South Wales (NSW). Emergency responders witnessed the man escaping his car and climbing onto a tree near the riverbank, but rescuers were not able to reach him before he was swept away. Police found a body in the area on Saturday and said it "is believed to be that of the missing man".

In a separate incident on Saturday, 13 military personnel were injured in a convoy crash in Lismore, about 200 kilometers south of Brisbane, according to Federal Defence Personnel Minister Matt Keogh. One truck overturned while driving on a narrow road. A second truck then collided with it.

The state's ambulance service had earlier said it treated 36 people in the accident. Keogh clarified to the media that while around 36 people were involved, only 13 were injured. They had been part of military crews deployed to Lismore, near the Queensland border, to help rescue and response operations.