Kamatapur Liberation Organisation (KLO) was formed in 1995 by the Koch-Rajbongshi tribes to carve out a separate Kamatapur State, comprising six north Bengal districts and Goalpara district in lower Assam through an armed struggle. Tushar Das alias Jibon Singha is the Chairman of KLO. Reports indicate that a large number of KLO activists received training in arms at the United Liberation Front of Asom (ULFA) camps in neighbouring Bhutan. There are also reports of growing terrorist and subversive activities of KLO in league with ULFA militants. In some instances, KLO militants have been reported to sneak into Assam after committing violent activities in West Bengal.

The KLO has carried out several joint operations with the ULFA in north Bengal, including abductions, killings, looting and extortion from tea gardens since 1999. The KLO in exchange for money and arms, provides shelter to ULFA cadres, operating from camps located in the jungles on the Bhutanese side, barely 10 km north of central Dooars. The first reported ULFA-KLO armed operation was the abduction of a tea garden owner from Latabari tea estate in north Bengal in July 1999. In November 1999, ULFA and KLO militants looted cash belonging to the Railways near Siliguri. KLO militants gunned down a local Communist Party of India (Marxist) leader in Ghogsapara near the Assam-West Bengal border in Jalpaiguri district on May 4, 2000.