Guwahati, Two top NSCN (IM) activists, including a self-styled major, were arrested in Assam and arms and ammunition were seized in separate operations by the Indian Army and state police, officials said on Sunday.

A Defence spokesman said that Indian Army in a joint operation with Assam Police apprehended an NSCN (IM) rebel, Raju Bramo, near Lalpahara in the Tinsukia district on Friday.

In another development, a self-styled major of NSCN (IM) Nyaoba Konyak alias Nweypa was apprehended near Titabor in Jorhat district on April 23.

Defence Public Relations Officer Lt Col P. Khongsai said two US-made Beretta pistols with two magazines, one point 22 pistol and four live rounds of ammunition were recovered from the rebels who were later handed over to the Assam police.

It is suspected that NSCN-IM's Nyaoba Konyak was actively involved in extortion and kidnapping activities in upper Assam, Lt Col Khongsai said.

The National Socialist Council of Nagaland (Isak-Muivah), which had several rounds of negotiations with the Indian government in Delhi as well as outside India after signing a ceasefire pact in August 1997, is one of the most influential rebel groups in the northeastern region.

The BJP government, led by Prime Minister Narendra Modi, had signed a "framework agreement" with the NSCN-IM leadership in 2015. Nagaland Governor R.N. Ravi is also the Centre's interlocutor to hold talks with NSCN (IM) and other Naga outfits.