Poachers killed a female rhino in the Bherberi area under the park's Kohora forest range late on Thursday evening. The de-horned carcass was found by the park officials on Thursday.

The officials heard a gunshot, but, by the time they reached the spot, the poachers had chopped off the horn and fled. Officials said an operation to find the poachers has been launched in areas on the fringes of the park.

With the latest killing, the rhino casualty figure in Kaziranga since January this year has reached nine.

Seven poachers have been gunned down by the Kaziranga officials since January this year.

The last rhino was killed in the Agoratoli forest range of the park last month.

In last month's rhino census operation, Kaziranga recorded an estimated 2,401 rhinos, showing an increase of 72 rhinos from the 2013 figure of 2,329. Frequent incidents of poaching, however, poses a major challenge for the state government. Different organizations are up in arms against the government's failure to curb poaching.

Soon after Thursday's incident, activists of All Assam Students' Union (Aasu) took to the streets in Kaziranga and criticized the state government for failing to check the menace. They blocked NH-37 for an hour to register their protest.

Union minister for environment, forests and climate change (MoEFCC), Prakash Javadekar, last month said here the centrally-funded, special anti-poaching squad would be deployed soon to take on poachers.