It's not clear why Ms Banu was abruptly sent to Bangladesh and then brought back. The BBC found at least six cases where people said their family members had been picked up, taken to border towns and just "pushed across". Officials from India's Border Security Force, the Assam police and the state government did not respond to questions from the BBC. But top sources in the Bangladesh administration claim that India "illegally pushed in" more than 1,200 people into the country in May alone, not just from Assam but also other states. In a statement, the Border Guard Bangladesh said it had increased patrolling along the border to curb these attempts.