SYDNEY, Jan 3: About 15,000 people battled 100 raging fires on Thursday on Australia’s east coast, news reports said.

Australia’s ABC radio reported that 20 houses were destroyed and more than 7,000 people were evacuated.

The New South Wales government announced it will buy two more water-bombing helicopters to help crews from around the country deal with the disaster.

The helicopters, which can hold 9,000 litres of water, have proved effective in fighting fires in the Blue Mountains west of Sydney. New units ordered are due to arrive within the next five days.

New Zealand offered the assistance of its firefighters, as recruits from all states and the Northern Territory help protect homes from fires that continue to surround Sydney.

Voluntary evacuations were underway at Oakdale in Sydney’s southwest, in Hawkesbury northwest of Sydney, and at Jervis Bay and Hyam’s Beach on the south coast, ABC radio reported.

Extra firefighting crews were being moved to the Blue Mountains west of Sydney, as winds continued to fan flames south of the Great Western Highway, a two-hour drive from Sydney.

Now deemed “black Christmas”, Australia’s bush fires continue to rage out of control in and around Sydney — home to four million residents.

Hot, dry windy weather continues to hamper efforts to extinguish the blazes that have destroyed more than 100 homes.

Twenty-one people have been arrested so far for allegedly starting the fires — most of them teenagers.—dpa