SINGAPORE: Lights went off in thousands of cities and towns across the world on Saturday night for the annual Earth Hour campaign.

Sydney’s Opera House and Harbour Bridge were among the first landmarks around the world to dim their lights for 60 minutes during the event, which was launched in the same Australian city in 2007.

An estimated 7,000 cities and towns from New Zealand to New York took part in the initiative.

Hong Kong’s stunning waterfront skyline was unrecognisable in the evening, with the city’s tallest skyscraper, the International Commerce Centre, stripped of the vast light show usually wrapped around its 118 storeys.

In the Indian capital of New Delhi, lights were turned off at major landmarks, including the India Gate.

In Pakistan darkness enveloped some 135 landmarks across the country when non-essential electric lights were switched off for 60 minutes at 8.30pm.

Taking part in the environmental campaign organised by the World Wildlife Fund-Pakistan, the Civil Aviation Authority saw to it that the hour was observed at all major airports in the country.

The staff of the Benazir Bhutto Islamabad International Airport organised a small walk to mark the occasion. Participants carried banners inscribed with slogans about conservation of energy and candles as they walked from Rawal lounge of the airport to its outer gates.

The hour was also observed at provincial legislatures, including the Sindh and Balochistan assemblies. Other important buildings where lights were switched off were the National Assembly, President House, Prime Minister House and Clock Tower, Faisalabad. —Agencies