TORONTO - Canadian cities joined cities around the globe in marking Earth Hour Saturday night, as people in central and eastern Canada switched off their lights.
  
The iconic CN Tower slipped into darkness at 8:30 p.m. local time, along with many of the skyscrapers in Toronto's financial district.

However, scattered lights were still visible after in some of the office towers in Canada's largest city.

At ground level, most stores and fast food joints along Yonge street, one of Toronto's busiest,  were switched on.

Huge crowds gathered at city hall for a free concert in the dark.

About 250 people gathered in Halifax's Grand Parade to watch the mayor turn off the city hall's lights.

Mayor Peter Kelly flipped off the lights on the building.

The two cities are among hundreds across Canada participating in the event, where people are encouraged to turn off or dim lights to raise awareness on global warming and climate change.

The event is part of an international effort sponsored by the World Wildlife Fund.

Kelly admitted he was a little disappointed that nearby office buildings left their lights on.

"We had thought everybody would be part of this process, and unfortunately, they are not," he said, gesturing to a nearby office tower where many lights remained on.

However, Kelly said when cities turn off municipal buildings' lights it "engages the citizens," and helps people feel they're part of a change in energy use across the globe.

"It shows that they care for their children and their grandchildren," he said.

"It gives us a chance to pause and think and consider what we can do for the future."

Nearby, astronomers trained their telescopes on the night sky, hoping to see stars more clearly.

Quinn Smith, a 59-year-old amateur astronomer, said Earth Hour allows him, "a chance at the night sky without the light pollution that's normally present at a city's centre."

In New York City, the Empire State Building was among the landmarks that shut off their lights to signal the need for global support for a new climate treaty.

The United Nations building was one of hundreds in New York City and around the world that went dark Saturday for an hour as part of an international action to highlight climate change. Sydney, Australia was the first major city to observe the rolling global blackout, known as Earth Hour.

Nearly 4,000 cities and towns in 88 countries planned to join in the World Wildlife Fund-sponsored event.