The hunters led by poacher Ishak Ali entered Pobitora for poaching of rhinos and fired upon the forest protection guards near Nekera Habi camp inside the sanctuary late last night.
As the forest guards retaliated, an encounter ensued leading to the capture of Ishak Ali. His associate, however, fled. None was injured in the encounter, the officials said.
Forest guards recovered a .303 rifle with several rounds of cartridges from the spot.
Police and Forest Protection Force have intensified their search operation to track down the fleeing poachers.
Located about 30 km of Guwahati, the 38.8 km sanctuary has a dense population of one-horn rhinoceros.
