Firefighters continued to battle two out-of-control blazes across New South Wales while investigations were under way into a suspicious fire which tore through bushland in the Royal national park south of Sydney.

The Royal national park was set to remain closed on Monday after a raging bushfire, which appeared to have been deliberately lit on Saturday, forced hundreds of hikers and tourists to be rescued by boat.

Firefighters with the help of a large air tanker worked throughout Sunday to contain the fire which had burnt more than 1,400 hectares of land.

On Sunday evening the blaze continued to burn along Sir Bertram Stevens Drive between Garie beach and Wattamolla beach, the NSW Rural Fire Service said.

The fire was being treated as suspicious with an investigation under way, a NSW police spokeswoman said.

The federal treasurer, Scott Morrison, who lives in Sydney’s south, paid tribute to the firefighters who worked throughout the weekend to bring the blaze under control.

“They’re out there in what is a very hot day in Sydney fighting those fires, they would otherwise be at the beach be with their families, sitting around the pool, attending family events, doing all of those things that the rest of us may be doing today,” Morrison told reporters in Sydney on Sunday.

“They are out there putting themselves at risk to keep our community safe ... I want to thank them very much.”

Further south in the southern tablelands, a bushfire had burnt more than 1,100 hectares at Bannaby and on Sunday afternoon was at watch and act level. The fire had increased in activity and embers created spot fires in the area, the RFS said. A water bombing aircraft was helping firefighters to prepare and protect rural properties as the out-of-control fire continued to burn.

Firies were also paying close attention to a large bushfire at Dandry in the state’s north that had already destroyed more than 51,000 hectares. The blaze, which was burning in the Pilliga forest between Coonabarabran and Narrabri and to the east of Baradine, was at a watch and act level.

NSW has endured hot, dry temperatures for several days, with Monday expected to bring no relief.

Total fire bans were declared for the southern ranges, central ranges, greater Hunter and north western regions on Sunday and would continue on Monday for the southern ranges, central ranges, greater Hunter and greater Sydney.

On Sunday most of NSW sweltered through temperatures above 40C, with residents in the state’s outback copping the worst of the heat.

Hay in the Riverina region was the hottest place in NSW, reaching 45.4C, while a blistering 40.3C made Penrith the hottest location in Sydney, the Bureau of Meteorology said.

Much of central and western NSW reached temperatures at or above 40C on Sunday after experiencing similar levels on Saturday.

Temperatures were expected to increase in western parts of Sydney on Monday and remain above 40C for NSW inland areas, meteorologist Jordan Notara said.

Residents in far-north NSW should brace themselves for temperatures above 45C on Monday.

“We’re not having any major changes in temperatures, unfortunately, generally over the whole state the severe heatwave is predominantly going to continue,” Notara said.

“Inland parts are seeing temperatures generally staying at 40C for the next seven-day forecast.”



