Migration continued , primarily from East Pakistan to India , right up to the liberation of Bangladesh in 1971 , both on an ongoing basis and with spikes during periods of particular communal unrest such as the 1964 East Pakistan riots and the 1965 India-Pakistan War , when it is estimated that 600,000 refugees left for India . Estimates of the number of refugees up to 1970 are over 5 million to West Bengal alone . This includes around 4.1 million coming between 1946 and 1958 and 1.2 million coming between 1959 and 1971
1964 East Pakistan riots
1964 East Pakistan riots
East Bengali refugees