Homes are believed to have been destroyed by bushfires in south-eastern NSW where hundreds of properties have already been lost in blazes this summer.

Strong winds and high temperatures on Saturday night pushed the massive 177,000-hectare Border fire north towards Bega Valley while three separate blazes burning south-west of the region merged into one.

An unconfirmed number of homes have been lost in the Bega Valley, mayor Kristy McBain said. Credit:Louise Kennerley

Bega Valley Shire Council mayor Kristy McBain said an unconfirmed number of homes were lost in Wyndham and Tantawangalo in the blazes.

"This pushes our total losses in Bega Valley to well over 400," she said on Sunday.