Dozens of people are thought to have died as wildfires sweep across southeastern Australia. Police sources were quoted as putting the estimated death toll as high as 40 as temperatures of up to 47C and high winds fuelled the blazes. The Australian Broadcasting Corporation said at least 14 people have been killed and more than 100 homes destroyed. Wildfires are a natural annual event in Australia, but this year conditions are some of the worst in living memory: a combination of scorching weather, drought and tinder-dry bush. On Saturday temperatures in Melbourne soared to 46.4C - the highest on record. A major fire in parkland east of the city burned more than 160 hectares after jumping containment lines overnight, despite water bombs being dropped from aircraft. In New South Wales, authorities said more than 40 fires were burning, with bushfire emergencies declared in several places. Smoke covered many areas of Sydney, which came under threat from two fires late on Friday. Police blamed a fire that broke out in the inner-Sydney district of Lane Cove on Friday night on arson. The blaze burned several hectares of a national park within the Sydney metropolitan area, threatening nearby homes. Fire bans are in force in three states, and in South Australia a fire broke out just north of Adelaide. Fire officials have advised residents to stay and defend their homes against bushfires, as most homes are damaged not by the actual firefront but burning embers blown onto roofs.