The vast majority of Muslims in the region are Sunnis, but a large percentage of them express devotion to saints and Sufi leaders. There are countless Sufi brotherhoods. In Bangladesh, the primary Muslim sects are Sunni, with a total of 5.3% being non-Sunni Muslims, mostly Shia and Ahmadiyya. In India, Shia Muslims are 25-30% of the Muslim population.
One remarkable expression of Muslim devotion in Bangladesh is the annual Bishwa Ijtema (Global Congregation) that brings 5 million devotees together for three days to pray and listen to Muslim preachers. This massive gathering on the outskirts of Dhaka draws Muslims from across Bangladesh and 150 other countries. It is the one of the largest annual gatherings of Muslims in the world, second only to the Hajj (pilgrimage) in Saudi Arabia.
In both India and Bangladesh, Muslims typically live harmoniously with Hindus. There is a high level of inter-religious socializing among the elite, and Hindu-Muslim marriages are common. However, in both countries, there is growing alarm at the increasingly successful efforts of Wahhabi Islamists promoting political, factional, and violent Islamism (imported from Saudi Arabia), that is similar to the influential home-grown Deobandi Islamism of 20% of India’s Muslims.