On 23 December 2014, militants from the Songbijit faction of the National Democratic Front of Bodoland (NDFB(S)) attacked villagers in the Kokrajhar, Sonitpur, and Chirang districts of Assam, India. The attacks began at approximately 6:25pm and resulted in the deaths of around 65 unarmed Adivasi people, including 21 women and 18 children. The violence occurred during preparations for Christmas, and most of the militants as well as the Adivasi victims were Christians. The attacks came two days after Assam Police killed two NDFB cadres on 21 December 2014, an action the NDFB(S) had warned it would retaliate against.
The NDFB, a militant group active since the late 1990s, has fought for a separate Bodoland homeland. While the main NDFB signed a ceasefire with the Indian government in 2005, the NDFB(S) faction, led by I K Songbijit, refused to give up militancy. The government had previously attributed a similar May 2014 attack on Muslim migrants to NDFB(S), though the NDFB denied involvement in that incident.
Following the December attacks, thousands of Adivasi people marched in protest the next day. At Dhekiajuli in Sonitpur district, police fired on the crowd when the protest turned violent, killing three Adivasi protestors. In retaliation, Adivasi people killed three Bodo people in a village near Behali in Sonitpur district. The combined death toll from the initial attacks, police firing, and retaliatory violence reached 85. Both communities burned houses and damaged property across the state, and the violence spread to Udalguri district as well.
In the aftermath, a curfew was imposed in parts of the three affected districts, and 55 companies of central paramilitary forces were deployed. The National Investigation Agency was assigned to investigate. Union Home Minister Rajnath Singh, Minister of State for Home Affairs Kiren Rijiju, and Minister of Tribal Affairs Jual Oram visited Assam and met with Chief Minister Tarun Gogoi. Prime Minister Narendra Modi announced compensation for victims' families, as did the Assam state government. By 26 December, about 72,675 people had been moved to relief camps.
On 26 December 2014, the Indian government launched "Operation All Out," an effort to eliminate NDFB(S) militants involving an estimated 9,000 personnel from the Indian Army and Central Reserve Police Force, along with additional Sashastra Seema Bal personnel. Subsequently, a joint delegation from the All Bodo Students' Union and the All Adivasi Students' Association of Assam visited relief camps to appeal for community unity and support the displaced villagers' return home.