Bongal Kheda refers to an organised campaign of ethnic cleansing of the Bengalis in the North East, that originated in the Brahmaputra Valley of Assam during the 1960s and 1970s and spread to Meghalaya and Tripura in the 1980s. During its peak in 1960, around 50,000 Bengali were expelled from Assam, who took shelter in West Bengal.
In 1960, Assamese mobs attacked Bengali peoples settlements in the Brahmaputra Valley. The most gruesome violence took place in 25 villages of Goreswar in Kamrup district. An one man enquiry commission was set up under Justice Gopal Mehrotra. According to the report nine Bengali were killed and more than one hundred were injured. There was at least one incident of attack on women. 4,019 huts and 58 houses belonging to the Bengalis were vandalised and destroyed. The District Magistrate of Guwahati who happened to be a Bengali was attacked by a mob of around 100 people inside his residence and stabbed. The Deputy Inspector General of Police, also a Bengali was also stabbed.
Thousands of Bengali were displaced from the Brahmaputra Valley and they subsequently migrated to West Bengal, tripura and Barak Valley. According to one estimate 500,000 Bengali were displaced from Assam. In West Bengal, thousands of refugees arrived in phases. The first batch of around 4,000 refugees arrived between 5 and 11 July 1960. The next batch of 447 arrived between 12 and 20 July. The rest arrived after 31 July. During July – September, around 50,000 Bengalis took shelter in West Bengal.
In 1972, large scale ethnic riots erupted in Assam, where the Bengali were mostly targeted. Around 14,000 Bengali fled to West Bengal and elsewhere in the North East.
During the first phase of the Assam Agitation, Bengali settlements were attacked throughout the Brahmaputra Valley. The cold blooded killing of Rabi Mitra, an ethnic Bengali technical officer at Oil India's headquarters in Duliajan caused widespread panic among the Bengalis. In 1983, the Bengali were attacked again during the anti-foreign agitation. In Dhemaji district, the Bengali were by the Assamese students in Silapathar.