Two local munia birds were used by Central Coalfields Limited authorities while conducting rescue operations in a mine where 14 miners were trapped in an accident 10 days ago. Nine bodies have been recovered so far, the Hindustan Times reported.

Authorities have been using the sensitive birds to detect poisonous gases – such as carbon monoxide - when attempting the rescue. “We have more faith in the munia than any advanced technology and the equipment used in mines," miner Ram Prakash said.

The birds are followed around the mine and their behaviour monitored – when a poisonous gas starts escaping, the birds try to escape, fall unconscious or die, signalling the need for a quick getaway.

Undergound coal mines have a long history of using canaries underground in detecting harmful gases. The practice was only phased out of British mines in the mid-1980's.