“Of these nine million, more than six million names were struck off as absentee or deceased voters, while the fate of another 2.7 million - including families like Ali's - remains undecided and will be determined by tribunals.”

“Thirteen states and federally-administered territories have undergone the SIR process so far, but West Bengal is the only one where it was followed by an additional layer of special adjudication.”

“India's Election Commission says the revision is meant to weed out duplicate or outdated entries and add genuine voters.”

“The tensions have been fuelled by remarks from political leaders, including from Prime Minister Narendra Modi, who have suggested in campaign speeches that the clean-up is aimed at identifying so-called "illegal Bangladeshi infiltrators" - a term the TMC says is being used to refer to Muslims.”

“India shares a 4,096km (2,545-mile) largely porous and partly riverine border with Bangladesh and a significant stretch of it runs through West Bengal.”

“West Bengal is also home to India's second-largest Muslim population, accounting for roughly 14% of the country's 172 million Muslims, according to the 2011 census.”

“Home to more than 70 million voters, the state has been governed by Chief Minister Mamata Banerjee's TMC since 2011, with Modi's Bharatiya Janata Party (BJP) as its main challenger.”