More than 1,000 Naga rebels were arrested by security forces since the banned NSCN-K attacked an Army convoy and killed 18 soldiers in Manipur two years ago, officials said.
As many as 531 underground cadres of NSCN-K and 542 overground workers were arrested in Manipur and Nagaland following intensive operations which began after the June 4, 2015, attack on the Army personnel.
"The operations are continuing even now and security forces have been able to restrict the NSCN-K's movement to a great extent," a home ministry official said.
This was for the first time in a decade that such a large number of Naga militants were arrested in just two years, the official claimed.
During the last two years, the security forces also killed 34 NSCN-K militants and recovered 571 sophisticated arms from arrested underground and overground cadres of the group.
After the June 2015 attack, the Indian Army had carried out a surgical strike on the camps of NSCN-K, killing some militants and destroying the camps.
Security forces also arrested 37 militants belonging to NSCN-IM, 26 militants belonging to NSCN-KN and four others from NSCN-R, the official said.
While the NSCN-K had abrogated the ceasefire agreement on March 27, 2015, the other three Naga insurgent groups have been maintaining the ceasefire agreement which they had signed with the central government a few years ago.
On December 8, Union Home Minister Rajnath Singh had said the violence perpetrated by insurgent groups in the Northeast has come done significantly -- by 75 to 80 per cent.
He also said the central government is committed to do its best to fulfil the aspirations of the Naga people for a brighter future but ruled out integration of the Naga-inhabited areas of Arunachal Pradesh, Assam, and Manipur.
Expectations for lasting peace have gone up in Nagaland, which has been hit by decades of insurgency, after the Centre and the NSCN-IM signed a framework agreement in 2015.
Early this month, President Ram Nath Kovind had said Nagaland was at the threshold of making history as the final agreement on the Naga political issue would soon be arrived at and a lasting peace achieved.
On September 19, Nagaland Governor P B Acharya said the vexed Naga issue would be solved within the next few months.