The carcass of another horn-shorn rhino was also found from the newly acquired sixth addition area of the World Heritage Site, taking the toll to four in the first 10 days of this new year, but there was some consolation for the forest department when its guards gunned down a poacher in Orang National Park early today.

Environment and forests minister Rakibul Hussain discussed the latest incident of poaching in the Burpahar range of the park with the principal chief conservator of forests (wildlife) R.P. Agarwalla, and given the "sufficient evidence of involvement of extremists and use of sophisticated arms", called for the army to assist the forest department.

"Necessary action has been initiated," Agarwalla said in a statement today.

Following the discussions between Hussain and Agarwalla, the forester convened a meeting at the Kaliabor circuit house in Nagaon, attended by police and forest officials, wherein it was decided that the request for deployment of the army on the southern boundary and peripheral areas will be made to district magistrates of Nagaon, Golaghat and Karbi Anglong.

It also resolved that a joint patrolling by police, Assam Forest Protection Force and forest staff, under the command of subdivisional officer Kaliabor, will be undertaken with immediate effect.

"We have seen poachers using M16 rifles earlier but this is the first time that empty cartridges of LMGs have been recovered," a forest official said, about last night's killing, adding, however, that the weapon was more to keep forest guards at bay than to kill animals. "But their intent is clear. They are here to stay and plunder," he added with a note of caution.

Forest guards are generally armed with .315 and 12 bore rifles while their accompanying home guards are provided with the antiquated .303 rifles.

Kaziranga officials said the group of poachers was armed with LMGs and AK series, apart from .303 rifles, and probably came from the adjacent Karbi Anglong hills. "Our men were fired upon from LMGs and AK-47 rifles when they tried to chase them in the dead of the night," Jinaram Bordoloi, the ranger of Burapahar range, told The Telegraph. He said spent cartridges of LMGs, AK-47 and .303 rifles were recovered from the incident site.

The official said it was around 1.40am today when a gunshot was heard near the Bahubeel area.

"It was a muted sound... probably the poachers used a silencer to kill the rhino. But the forest guards who were on duty in the area immediately rushed to the spot and accosted the group of poachers," the official said.

The poachers, the official said, had crossed over a nullah and started firing at the forest guards from LGs and AK-series rifles. "Our men had no option but to give up the chase. It took less than 10 minutes for our men to reach the place," the official said.

The carcass of the female rhino was recovered later from the incident site with its horn missing.

In the second incident, the carcass of another rhino was recovered from Buroimukh near Gohpur in Sonitpur district, which is in the sixth addition area of Kaziranga late yesterday. Forest officials claim that the rhino was killed nearly a week ago. The horn was missing.

In another development, a poacher was killed at Orang National Park in the wee hours today. A .303 rifle, four live cartridges, a bag containing food and an axe, were recovered from the site.

Conservator of forest, Mangaldoi forest division, Sushil Kr Daila, under whose jurisdiction the park falls, said a group of three poachers was accosted by the forest guards near Rowmari camp around 2am today. "When the poachers were challenged they fired upon the forest guards and in the exchange of fire one poacher died, while the others escaped," Daila said.

The victim has not yet been identified.

The poachers were first spotted by the forest guards at the Panchnoi camp number 2 observation post, who subsequently raised the alarm.

Orang has witnessed the killing of two rhinos last year, both in December. Poachers killed a pregnant rhino on the night of December 31.

Last year, 32 rhinos were killed and 41 the previous year.

The spate of killing of rhinos has triggered protests from several quarters in the state and the newly appointed Assam governor Padmanabha Balakrishna Acharya has also expressed deep concern, hurt and anger. He has instructed the authorities to identify the persons accountable for such heinous crimes and punish them severely without mercy, according to the law.

Even today, members of the All Assam Students' Union staged protests at Kaziranga while condemning the killing of rhinos and demanded the forest minister's immediate resignation.