A flood-hit community is devastated after two bodies were found in an inundated vehicle during a search for missing backpackers.

Police say they believe the deceased are a 26-year-old man and 23-year-old woman — believed to be Chinese nationals — who disappeared while driving from Brisbane to Queensland’s flood-ravaged North Burnett region.

Over in the Northern Territory, a driver and passenger were winched from their car while caught in raging floodwaters before rescuers went back for their German Shepherd.

In incredible footage, a police officer is seen dropping from a helicopter onto the 4WD car to save the stranded driver and passenger.

Helicopter pilot John Armstrong Jnr told ABC Radio Darwin that getting the dog out of the vehicle was difficult.

“The [police officer] did all the hard work. I just had to drop him off and pick him up,” Armstrong said.

“It took him quite a while to get the dog out of the motor car, because of course it was electric windows and so he had to take the baton out there … crawled down and stand on the side rail and smash the front window.

“At one stage, [the dog] did try to jump past him into the river and he managed to stop it but then it disappeared into the back of the car, so he had to move along and smash in the back window and it took him quite a while to wrestle the dog onto the roof.

“He basically laid on top of the dog to hold it down while I came in to pick him and the dog up.

“Obviously, getting people into choppers is one thing but trying to convince a dog to get into a chopper, yeah that was a bit difficult.”

The first flood-related deaths in Qld’s rain-hit Gympie region has devastated the community after the bodies were found, local mayor Glen Hartwig said.

“They are two young people who have sadly passed away,” he told AAP.

“For their families who have to deal with this heartache, our thoughts and prayers go out to them.”

The disappearance sparked a search of the area from Kilkivan to Mundubbera, west of Gympie, where floodwaters had inundated communities.

Police, SES volunteers and helicopters scoured the region from Wednesday morning, later locating a silver vehicle at Kilkivan Tansey Road.

Police later confirmed two bodies had been found in the car, with divers and forensic teams remaining at the scene to investigate.

The region near where the vehicle was found had been one of the hardest hit by wild weather, Hartwig said.

Up to 400mm of rain fell in 24 hours before floodwaters “absolutely smashed” western areas including Kilkivan, Goomeri, Woolooga, Tansey and Manumbar.

Crops, fences and roads were destroyed but the full extent of the damage won’t be known until floodwaters recede.

“There’s significant infrastructure damage. It is going to take a long time to repair,” Hartwig said.

“Looking at the financial impact on farmers, it will be 12 months before they will take any money from these paddocks that have been destroyed.”

The central Queensland city of Bundaberg has been hit with its third major flood in 16 years. Photo: AAP/McGrath Knight Frank Bundaberg

The Chinchilla community northwest of Brisbane is next in line after Bundaberg was flooded on Wednesday, inundating hundreds of houses and businesses.

Police issued an emergency declaration at Chinchilla, setting up an exclusion zone in the Western Downs town as floodwaters threatened.

An evacuation area has been established at the Chinchilla showgrounds, with at least 10 businesses inundated.

Chinchilla’s flooded Charleys Creek was expected to reach a 6.8-metre peak on Thursday, local mayor Andrew Smith told AAP.

Residents are clinging to hope that Charleys Creek, which runs through the town, would not reach the devastating flood levels of 2011.

Back then, Charleys Creek reached a record peak of 7.45m, flooding scores of homes and damaging the prized local watermelon industry.

Door-knocking began in the community’s low-lying areas late on Wednesday warning residents to evacuate before a number of people were reportedly rescued from a campground.

Further west, Longreach is bracing amid fears low lying houses may be impacted in the coming days.

In the Northern Territory, multiple flood warnings and watches are in place across the saturated Top End.

The clean-up has begun at Katherine but hundreds remain in emergency shelters after their homes were inundated and some are still without power.

The nearby Katherine River was likely to peak at 17 metres on Thursday night.

Darwin and Palmerston residents have been told to keep boiling water despite nearby dam pumps restarting after they were shut down by flash flooding.

A mother and her children were rescued from a roof when flash flooding hit south of the NT capital on Monday, swamping about 20 homes,

The federal and NT governments on Thursday announced extended assistance to flood-hit communities.

-with AAP