SYDNEY, Nov. 23 (Xinhua) -- Authorities on Friday declared a bushfire emergency in the Hunter region of Australia's New South Wales state, with the spreading inferno threatening more homes and strong winds hampering firefighting efforts.

The fires were burning in at least three major areas north of state capital Sydney and razed about 1,380 hectares, according to the state's rural fire service.

"The fire is spotting in a number of areas under strong winds, which are expected to continue in the area today and this will hamper firefighting efforts," it said in a statement.

More than 200 firefighters were battling the flames, with aircraft such as heavy tankers also deployed, local media reported.

"The fire is burning very aggressively and moving very quickly," the fire service's commissioner Shane Fitzsimmons told the ABC news channel.

The fires were continuing to threaten properties, with at least two sheds destroyed overnight, according to authorities.

Emergency alert telephone warning messages were sent to people in the affected areas and they were advised to seek shelter, said the fire service.