The All Tripura Tiger Force (ATTF) was orginally founded as All Tripura Tribal Force in 1990 by a group of former Tripura National Volunteers (TNV) terrorists, who dissociated themselves from the TNV when the August 1988 Accord was concluded between the TNV and the Central government, and refused to surrender as required by the Accord.

ATTF militants have been demanding the secession of Tripura from India and the expulsion of Bengali-speaking immigrant settlers from the State. The political wing of the ATTF – Tripura Peoples’ Democratic Front (TPDF)-- has set up a parallel government in the remote areas of the State. The outfit's cadre strength is reported to be 400.

The ATTF was initially a small group of tribal extremists operating in pockets of North and South Tripura districts. But soon, the insurgent group began mobilising manpower by recruiting tribal youth and enhancing the fire power of its cadres. By 1991 it emerged as a formidable terrorist group.

The ATTF is involved in a variety of terrorist activities--series of attacks on police stations, police outposts, buses and trucks, abduction of government officials for ransom and killing of civilians and security force personnel, in various parts of the State. In order to tackle the situation, a massive combing operation was launched in Tripura against the ATTF.

That apart, under an amnesty offered by the State government more than 1,600 militants surrendered by March 1994 . However, a group of ATTF cadres did not surrender. This group revived the ATTF under the leadership of Ranjit Debbarma who continues to be its President. The ATTF continued its violent campaign and was subsequently banned in April 1997, under the Unlawful Activities (Prevention) Act, 1967.The ATTF suffered a setback in February 1998 when a large quantity of arms was seized from its activists in the Andaman Sea by the Indian Navy under Operation Leech.

ATTF cadres have received training in the Chittagong Hill Tracts(CHT), in Bangladesh. The group has a number of bases there. Also, It has forged links with some of the militant groups operating in the Northeast – United Liberation Front of Asom (ULFA), People’s Revolutionary Party of Kangleipak (PREPAK) and People’s Liberation Army (PLA).