The history of sectarian conflict in Assam's Bodo-dominated pockets dates back to the 1967 movement for Udayachal, a proposed separate state for the indigenous tribe.
The inflow of Muslim immigrants from neighbouring Bangladesh touched a raw nerve with the Bodos, which started blaming the settlers for illegally encroaching on their land.
The Udayachal movement failed, but the growing discontent reared its ugly head in the 1970s, when the inflow of Muslim settlers increased in what is now known as the Bodoland Territorial Areas District (BTAD).
The four districts under BTAD are: Kokrajhar, Baksa, Chirang and Udalguri. The ethnically volatile region is under the Bodoland Territorial Council (BTC), which came into existence in 2003 after the militant group Bodo Liberation Tigers Force — it championed the cause for a separate statehood — surrendered.
The BTC accord was signed with the objective to fulfill the aspirations of the Bodo people regarding their cultural identity, language, education and economic development. Immigrant Muslims in lower and northern Assam, however, opposed the creation of the BTC.
Before that, the All Bodo Students' Union (ABSU) in 1987 had started a fresh separate Bodoland statehood movement with the slogan of Divide Assam 50: 50.
Major clashes gripped Assam during the movement, which ended with the ABSU signing the Bodoland Autonomous Council Accord in February 1993. In the same year in October, 50 people were killed in Bongaigon district adjoining Kokrajhar.
The BAC was dissolved and the ABSU kick-started a new movement. Some Bodo youth took up arms and formed the Bodo Liberation Tigers Force (also known as Bodoland Liberation Tiger) in the mid-1990s.
A series of ethnic clashes took place in lower and western Assam. Immigrant Muslims were the worst sufferers.
Territorial dispute between the Bodos and the Muslims are blamed for the clashes in Udalguri district in 2008 and and Kokrajhar in 2012.
Two years ago, ethnic clashes left 108 people, mostly Muslims, dead and 2.5 lakh displaced in Kokrajhar.