Widespread riots between Hindus and Muslims took place in Calcutta following the All-India Muslim League's call for an independent Pakistan.

Direct Action Day was the day the All-India Muslim League decided to take a "direct action" using general strikes and economic shut down to demand a separate Muslim homeland after the British exit from India. Also known as the 1946 Calcutta Riots, it soon became a day of communal violence in Calcutta. It led to large-scale violence between Muslims and Hindus in the city of Calcutta in the Bengal province of British India. The day also marked the start of what is known as The Week of the Long Knives. While there is a certain degree of consensus on the magnitude of the killings, including their short-term consequences, controversy remains regarding the exact sequence of events, the various actors' responsibility and the long-term political consequences.

Kolkata, also known as Calcutta, is the capital and largest city of the Indian state of West Bengal. It lies on the eastern bank of the Hooghly River, 80 km (50 mi) west of the border with Bangladesh. It is the primary financial and commercial centre of eastern and northeastern India. Kolkata is the seventh most populous city in India with an estimated city proper population of 4.5 million (0.45 crore) while its metropolitan region Kolkata Metropolitan Area is the third most populous metropolitan region of India with a metro population of over 15 million. Kolkata is regarded by many sources as the cultural capital of India and a historically and culturally significant city in the historic region of Bengal.

The All-India Muslim League (AIML) was a political party founded in 1906 in Dhaka, British India with the goal of securing Muslim interests in India. Although initially espousing a united India with interfaith unity, the Muslim League later led the Pakistan Movement, calling for a separate Muslim homeland after the British exit from India.