New South Wales has declared a state of emergency for the next 30 days as fire-fighters try to contain the worst bushfires the state has seen in four decades.

Over 200 homes have already been destroyed and 120 damaged by the fires which broke out across the state earlier this week.

More than 37,000 hectares (91,400 acres) have been affected.

One man has been killed as he attempted to protect his home, according to reports.

Conditions look set to worsen over the next few days as soaring temperatures and strong wins continue to fan the flames.

Popular tourist spot, The Blue Mountains, west of Sydney, has been the worst affected area.

Authorities have warned that the three main bushfires - two in the Blue Mountains and one near the town of Lithgow - could become one huge fire in the coming days.