Australian emergency crews struggle to get control of bush fires around Sydney, while the police make progress in the hunt for arsonists believed to have set some of the blazes. Police have arrested several suspects.

Australian police are carrying out the promised crackdown on suspected arsonists. Three teenagers, all boys aged 15, have been arrested on suspicion of starting small fires near Sydney. They may not face formal charges, if they agree to undergo psychological counseling.

A 19-year-old man also has appeared in court in the nation's capital Canberra, charged with arson.

Lighter winds and cooler conditions Friday helped more than 5,000 emergency workers on the front line, which stretches for hundreds of kilometers around Australia's biggest city.

The outlook for the next few days, however, is not good in the state of New South Wales.

The state's Emergency Services minister, Bob Debus, said the next 72 hours would be 'extremely difficult.'

Weather forecasters predict soaring temperatures, strong winds and low humidity Saturday and Sunday, which will help further spread the flames. Hundreds of fires still burn. The Royal National Park, one of the world's oldest national wildlife parks, has been ravaged, with 80 percent of its area burned.

To the west in the Blue Mountains, a 30-kilometer line of fire threatens several communities.

The lush farmland and mountain areas in New South Wales are always prone to fires, especially in December and January, during Australia's long, dry summer. The New South Wales fire commissioner, Phil Koperburg, said many communities will always be vulnerable to fires. "We, obviously, can't hazard-reduce New South Wales," he said. "Fire is part of the ecology of this country. It has been around for 60,000 years, or more, and, all of a sudden, we find ourselves in a position where all of our assets are in places where there are historically fires."

Four-thousand people have fled their homes across the fire zone in New South Wales; about 160 homes have been destroyed. No deaths or serious injuries have been reported, however.

Local firefighters have been reinforced by crews from around the country. Firefighters' unions are calling on the state government to bring in special planes from North America, which can drop huge amounts of water on the blazes.