TONGI, Bangladesh (AFP) - At least two million worshippers gathered north of the Bangladeshi capital Dhaka Friday for a three-day event billed as the largest annual Islamic event after the hajj. Columns of thousands of devotees " most carrying beds and utensils " have been streaming towards the gathering site on the banks of the river Turag at Tongi for the Bishwa Ijtema, or World Muslim Congregation. The gathering, at which Muslims pray and listen to religious scholars, was first held in the 1960s and was launched by Tabligi Jamaat. "I've come to learn from our elders. It's very tough times for Muslims across the world and I hope this Bishwa Ijtema will strengthen our faith and make us true believers," said Mohammad Ishaq, a trader from Pakistan. Organisers said some 6,000 foreigners from more than 100 countries have attended the event but most of the worshippers are from rural areas of Bangladesh. "It's fifth year I am here. Every time I went back to my village I became a better Muslim. It's like a hajj for poor people like us and it purifies your soul," said Zakir Hossain, 48, a farmer from the northern Bangladesh district of Dinajpur. Local police chief Abdul Baten said more than two million people were taking part this year, with the crowd spilling over from the tented venue to roads and highways leading to the river. Security has been tight with some 11,000 police and elite Rapid Action Battalion officers deployed, he said. Police have set up scores of checkpoints and closed circuit television cameras as part of security measures. Helicopters and speedboats have been kept on standby. The government has arranged special trains, while army engineers have set up dozens of makeshift bridges and water tanks. After a series of sermons and prayers over the next three days, the congregation will conclude with a noon prayer on Sunday when some three million people are expected to attend. Bangladesh is the world's third-largest Muslim-majority nation, with Muslims making up nearly 90 percent of its 144 million population.