The incident came to light after park officials found the carcass of a rhino in the Balipukhri area of the park's Agoratoli forest range on Friday, Kaziranga divisional forest officer Suvasish Das said.

On Wednesday evening, park officials heard the sound of gunshots but could not find the carcass. Since then, a massive search operation had been on.

Forest minister Pramila Rani Brahma, who rushed to Kaziranga to take stock of the situation, said she would determine what needed to be done to strengthen anti-poaching measures.

Kaziranga has lost at least 11 rhinos to poachers this year. The park is home to two-thirds of the world's one-horned rhinos.

On August 3, poachers killed a female rhino and her calf just as the park was limping back to normal after the devastating floods in which more than 300 animals were killed.

Recently, chief minister SarbanandaSonowal held a meeting with his Nagaland counterpart, TR Zeliang, in Kaziranga and raised the issue of inter-state cooperation to curb poaching.

Poachers often smuggle horns from Assam to Nagaland and then to Myanmar through the border town of Moreh in Manipur.

The horns are in high demand in Vietnam and China where they are used in traditional medicine.