An estimated 3.5 million Hindus and Sikhs living in West Punjab, North-West Frontier Province, Baluchistan, East Bengal and Sind migrated to India in fear of domination and suppression in Muslim Pakistan. Communal violence killed an estimated one million Hindus, Muslims, and Sikhs, and gravely destabilised both dominions along their Punjab and Bengal boundaries, and the cities of Calcutta, Delhi and Lahore. The violence was stopped by early September owing to the co-operative efforts of both Indian and Pakistani leaders, and especially due to the efforts of Mohandas Gandhi, the leader of the Indian freedom struggle, who undertook a "fast-unto-death" in Calcutta and later in Delhi to calm people and emphasise peace despite the threat to his life. Both governments constructed large relief camps for incoming and leaving refugees, and the Indian Army was mobilised to provide humanitarian assistance on a massive scale.