The NSW Rural Fire Service has downgraded a bushfire at Bemboka near Bega on the NSW South Coast from an emergency to watch and act, though at least one home has been lost.

The bushfire had been burning for several weeks. ( Supplied: Helmut Eder )

The fire burning near Yankees Gap Road was out of control from 3:00pm this afternoon, but about 7:00pm tonight the RFS said it had eased up.

One home in the area has been lost as a result of the blaze, with unconfirmed reports at least two others may have been damaged.

The fire has been burning for several weeks in the South East Forest National Park and borders on Numbugga, a small town with a population of about 125.

It is covering a 15,000 hectare area.

Earlier, RFS spokesman Greg Allen said residents in the area near Coopers Gully and Numbugga should take shelter as it was too late to leave.

A destroyed house in the hills near Yankees Gap. ( ABC News: Tom Lowrey )

"In the area there are a number of isolated rural properties with firefighters in the area working on this fire to contain it as soon as possible," he said.

Bushfire smoke billowing from Bemboka in Bega, in south coast NSW. ( Supplied: Rachel Helmreich )

"But under these very hot and very windy conditions … there are some spot fires and embers blowing ahead of that fire front, so it really is important, especially for those in the Bega area, to monitor the situation, monitor for embers and to follow your bushfire survival plan.

"It's very warm as it is in a lot of parts of the state today, and it's also very gusty as well, we're seeing very strong north-westerly winds and that's what's pushing this fire along.

"It's a fire that's been going for a number of weeks. It had settled down for a little while but under the conditions today we have seen that fire activity increase."

The fire has produced a large amount of smoke that has affected the Bega Valley.