A political row has erupted in India over allegations of "vote theft" by opposition parties, and accusations of electoral irregularities against the country's election body, which they say favoured the ruling Bharatiya Janata Party (BJP) in the 2024 general elections.

India's opposition accuses the Election Commission of India of rushing through a mammoth electoral roll revision in the eastern state of Bihar, saying the exercise could render vast numbers of citizens unable to vote.

Dozens of Indian opposition leaders were detained in New Delhi on Monday as they shouted slogans, jumped barricades and marched to the Election Commission in a rare public protest against what they say are electoral malpractices.