Dibrugarh: As many as 18 rare slender-billed vultures were found dead at Jamuguri Gaon in the Demow area of Sivasagar district on Sunday. According to a forest official, they died after eating a poison-laced carcass of a calf.

Three other vultures are in critical condition and provided veterinary care by a vulture-conservation team.

Talking to this correspondent on Sunday, Sivasagar divisional forest officer Bidya Bordoloi said the incident took place at Nitaipukhuri Jamuguri village near Pani Dihing wildlife sanctuary.

Bordoloi said the flock of vultures had died after consuming the poisoned carcass of a calf that was dumped in a paddy field on Saturday evening by goons. The official added that post mortemof the vultures confirmed that they had died of poisoning.

"We have lodged a complaint with police and very soon the culprit will be arrested. The birds belonged to the slender-billed vulture species which is extremely rare. Locals are also deeply saddened by the incident and promised full cooperation in nabbing the culprits," Bordoloi said.

The slender-billed vultures belong to the critically-endangered species and their population across the world is estimated to be anywhere between 1,000 and 2,500. Over the years the species has suffered rapid population decline especially in the Indian subcontinent as they feed on carcasses laced with poison and veterinary drugs.

It is, however, not the only incident of bird poisoning in Sivasagar district.

In February 2017, 17 migratory birds, belonging to the grey-legged goose species, were poisoned to death in the Dikhoumukh area of Sivasagar.

In January 2015 more than 50 vultures, including Himalayan griffon, white-backed and slender-billed vultures died after consuming a poisoned carcass of a cow in the Demow area.

In March this year, 36 Himalayan Griffon vultures died at Magorhut after they fed on a poisoned carcass. White-backed and slender-billed vultures fall under the "critically endangered category".