Sydney suffocates under blanket of smoke

SYDNEY, Australia -- Smoke from more than 100 bushfires continues to suffocate Australia's largest city, obscuring the tallest skyscrapers, the famous Opera House and Harbor Bridge with visibility cut to just a few hundred meters.

So far more than 250,000 hectares of bushland has been destroyed by the blazes, many of which were deliberately lit, including six new fires on Sunday.

The bushfires surrounding Sydney are being kept under some control by firefighters and residents who have battled the flames since Christmas Day.

Weather conditions remain relatively benign after forecasts of soaring temperatures and strong winds failed to materialize.

"The forecast weather has not eventuated in many parts of the state (New South Wales), the humidity is higher than anticipated, the northwesterly winds did not emerge at all," a relieved Rural Fire Service Commissioner Phil Koperberg told a news conference.

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But he warned the situation was still grave.

Visibility low

The smoke caused disruption at Sydney airport.

While takeoffs were unaffected, poor visibility forced the diversion of two domestic and three international flights to Brisbane and the capital Canberra.

Many of the main roads into the city have now been re-opened but driving is hampered by poor visibility caused by the smoke.

Harbor ferries packed with summer holiday makers used their foghorns to avoid collisions with small weekend pleasure craft. Asthma sufferers had to take refuge in air conditioned buildings.

"I can't see the Opera House," said one Taiwanese visitor as she looked across from the harbor's northern foreshore several hundred meters away.

The Blue Mountain national park district west of Sydney, the scene of some of the biggest fires, is blanketed with a dense grey suffocating smog.

Air quality 'grim'

The fires flared on Christmas Day as high winds fanned flames. More than 10,000 firefighters and support staff are battling with blazes to the north, west and south of the city.

Air quality has plunged. Health warnings from medical authorities advising people with respiratory problems to stay indoors have dashed usual year-end plans to relax at the beach in the sizzling summer heat.

"The advice we are giving people today is to stay indoors particularly if you do suffer from asthma or any other respiratory disease," said Catherine Havenaar of the New South Wales Ambulance Service.

"Pollution levels are very grim with smoke and dust and those working in the fire areas will find it particularly difficult today," she told Sky television.

Since Christmas Day the New South Wales Environment Protection Authority's regional pollution index (RPI) rocketed to around 200. The RPI was below 20 at this time last year.

More than 150 homes and properties, mostly south and west of the city, have been destroyed by the bushfires but there have been no reports of death or serious injury.

Reuters contributed to this report.