Sydney wildfires: Out of control blaze is among the worst in a decade

Emergency warnings have been issued and residents are being urged to take shelter

The bushfire thought to be one of the worst in a decade has hit areas in Australia, destroying dozens of homes as it sweeps across Sydney's north and south regions.

Hundreds of fire-fighters are now battling seven major fires across New South Wales. Residents who have not already been evacuated from surrounding areas are now being instructed to take shelter in their homes.

Dangerous weather conditions have fanned the flames, with fire-fighters in the area expecting "significant" home losses. Rural Fire Service Deputy Commissioner Rob Rogers told ABC Radio: “It's probably the most serious fire risk we've faced since the early 2000s.

“If we come out of this day without losing hundreds of homes we'll be very lucky.”

Strong winds expected to reach up to 80km and temperatures of over 30C have caused havoc for fire-fighters attempting to tackle blazes.

A fast moving fire in the north of Lithgow has so far destroyed more than 600 hectares of bushland and is threatening properties across Clarence and Oaky Park.

Evacuation centres have been set up at the Blue Moutains Botanic Garden at Mount Tomah and the Lithgow Workers Club.

The RFS said residents in the Balmoral Village, west of Wollongong should stay put now. "Basically we're just urging residents to take shelter. There's no time to leave now", Wendy Smith, RFS spokesperson told ABC news.

A team of 100 fire-fighters have also been working to douse a fire in the Blue Mountains, west of Sydney on Thursday.

Approximately 60 fires are burning across the state and 20 of these remain uncontained. Emergency response teams are now preparing for tougher weather conditions.