The Delhi government on World Environment Day on Monday opened for public a butterfly park at Asola Bhatti Bird Sanctuary to increase awareness about butterflies.

The park was built and is being maintained under the guidance of Bombay Natural History Society (BNHS).

Spread over 2.5 acres, the park had been made with minimum intervention and disturbance to the existing flora and fauna, said Sohail Madan of BNHS.

"The park has 60 varieties of native trees and we have planted over 25 species of host plants and more than 30 varieties of nectar plants. Till now, 64 species of butterfly have been registered in the park," he said.

The park has 60 varieties of native trees and over 25 species of host plants. 

More than 30 varieties of nectar plants had also been placed in the park, which would attract many common and rare species of butterflies, a statement said.

Delhi Development Minister Gopal Rai, who was the chief guest at the function, said: "We are working to conserve the environment since very beginning. It was us who brought the Odd-Even Formula in Delhi to protect the air of Delhi."

Environment Minister Imran Hussain said: "We should understand our responsibilities and create clean environment around us."