Howrah Bridge illuminated in blue on Friday evening to mark World Autism Awareness Day. April 2 is designated as World Autism Awareness Day by the United Nations. “Light it up Blue” is a campaign spearheaded by Autism Speaks, an organisation that works to create understanding and acceptance for persons with autism.

Supporters are encouraged to wear blue and post on social media with the hashtag #LightItUpBlue to raise awareness about the neurological condition.

Landmarks across the world have turned blue in solidarity this year, an official of the Calcutta Port Trust said.