Parliament Complex, Nirman Bhawan and Shastri Bhawan were among the government offices in Delhi where the World Earth Hour was observed by switching off lights between 8.30 pm and 9.30 pm tonight.
Lights were also switched off at Rashtrapati Bhavan, India Gate, Akshardham Temple in Delhi and Buddha Statue in Hyderabad and Howrah Bridge in Kolkata, according to an official from World Wide Fund for Nature (WWF), which organises the campaign.
Yesterday, Union Environment Minister Harsh Vardhan urged people to switch-off all non-essential lights for an hour today to mark the Earth Hour, saying he himself will do so.
Celebrities and politicians too vowed their support for the campaign.
Madhya Pradesh Chief Minister Shivraj Singh Chouhan tweeted a picture which showed him sitting in candle light.
Chouhan said: "I observed Earth Hour in my residence and worked in candle light. I hope you too did the same."
Delhi MLA Manjinder Singh Sirsa tweeted, "If you can read this, you can surely manage with lesser light for one hour. Let us switch off all non-essential lights in our offices & residence from 8:30 to 9:30 pm tonight in support of #earthhour. I support this wonderful initiative by @drharshvardhan."
Actor Amitabh Bachchan tweeted, "#EarthHour is tonight, Mar 24th .. #Switchoff all non essential lights between 8.30-9.30pm and join millions around the world .. !! Come together to #Connect2Earth."