A bushfire burning out of control on the outskirts of Hobart has been downgraded from emergency warning to watch and act.

Key points: The uncontrolled blaze broke out this afternoon near several homes outside of Hobart

The uncontrolled blaze broke out this afternoon near several homes outside of Hobart Glenlusk residents are urged to remain vigilant as fire in steep area can spread quickly

Glenlusk residents are urged to remain vigilant as fire in steep area can spread quickly An evacuation centre has been set up at Collinsvale Recreation Ground & War Memorial Hall

The blaze is burning at Collinsvale Road in Glenlusk, in a rural area north-west of the city, near several homes and communication towers.

It is unclear at this stage what caused the blaze, which broke out this afternoon.

Water bombing aircraft have been called in, while 30 fire crews are on foot working to bring the fire under control.

TFS regional fire controller Phil Smith said the area was extremely dry and any fire that spread uphill would move very quickly.

"It didn't catch us unaware, but we weren't expecting it," Mr Smith said.

"It's quite steep and undulating country … it's going to have to be attacked on foot.

"We've been concentrating more on protecting the assets and the communication like the NBN at the top of the hill.

"The towers up there contain all the communication assets for the Collinsvale area so we don't want to see any damage done to any of that infrastructure for the inconvenience and lack of communication it brings."

He said the fire had only gone through 10 hectares in the past hour, meaning the threat had eased.

Dozens of bushfires continue to burn across the rest of the state.

Six watch and act alerts are in place for the Fingal area, in Tasmania's north-east, and three advice warnings are in place in Pelham and in the state's south-west.

The weather bureau has forecast warmer temperatures over the weekend.