SYDNEY -- A bushfire in Australia's Victoria state more than trebled overnight and authorities urged residents in a remote part of Tasmania state to evacuate as a spring heatwave fanned fires across the country's southeast.

Around 17,000 hectares (66 square miles) were ablaze on Tuesday in the eastern part of Victoria state's Gippsland region after high winds spread fires overnight, according to state fire authorities, who had deployed some 650 firefighters.

"We moved in strike teams in the very early hours of this morning," said Jason Heffernan, chief officer at Country Fire Authority Victoria.

"It is quite a large fire spread across a large area. ... It's proving to be quite difficult, burning in private property but also some pine plantations."

New South Wales Rural Fire Service firefighters walk through a hazard reduction burn in Sydney, Australia, September 10, 2023. Photo: Reuters

Across the Bass Strait in Tasmania state, residents on the northern edge of Flinders Island were told to evacuate from an out of control bushfire.

Fires are being stoked by hot, dry winds across southeast as the country experiences an unseasonably hot spring.

Australia began spring with its driest September on record, according to the Bureau of Meteorology, with rainfall 71 percent below the 1961-1990 average.

Conditions are expected to change rapidly in Victoria Tuesday afternoon, with heavy rains expected to help douse fires but potentially trigger flash flooding.

"It's very concerning," said Heffernan. "There's a bit of a running joke down here in Victoria you can expect four seasons in one day and I gotta tell you, today, they're not wrong."

Hot and dry conditions also led New South Wales authorities on Tuesday to ban open fires across large swathes of the state, including the Greater Sydney Region. There were 82 fires burning across the state, 16 not contained, on Tuesday morning.

Temperatures are expected to hit 37 degrees Celsius (98.6°F) in Sydney's west on Tuesday afternoon.