The Bishwa Ijtema brings devotees from more than 60 countries to a sandy riverbank near the capital, Dhaka.
The gathering is said to be the second biggest Islamic congregation after the Mecca pilgrimage.
Participants spend time in prayer, discussing the Koran or listening to sermons. On Sunday the meeting concludes with a mass prayer session.
Tight security
For three days this tented city on the banks of the River Turag near Dhaka is packed with people from all corners of the world.
Spend a few hours among the crowds here and your ears tune to the roar of the gas stoves from thousands of temporary kitchens manned entirely by devotees themselves.
For Sunday's mass prayer, every available inch of open ground, rooftop or road will be filled with worshippers.
The final prayer is followed by a mass exodus as many devotees begin the two-hour walk back to Dhaka.
FROM BBC
