Raipur, Aug 18 - Authorities of a zoo in the Chhattisgarh capital have virtually given up hope to find a bear that went missing 11 days ago.

The female bear called Radha went missing from its enclosure at Nandan Van zoo Aug 7. The zoo is located on the outskirts of Raipur.

'We have been giving up hopes to find the bear. The way it went missing looks extremely surprising to us. But it looks like the bear used a branch of a tree to jump out of its enclosure and vanished into a nearby forested village,' zoo in-charge R.S. Mishra told IANS.

Mishra said efforts were being made to enlarge spaces of the enclosures for several animals.

He said a lioness and her three cubs, kept in a single enclosure that had some small trees, will be shifted to separate enclosures to reduce the risk of escape.