Bangladeshi Muslim devotees head to their homes in an over-crowded train after attending three-day Islamic Congregation on the banks of the River Turag in Tongi, 20 kilometers (13 miles) north of the capital Dhaka, Bangladesh, Sunday, January 26, 2014. Hundreds of thousands of Muslims attended the annual three-day event that is one of the world's largest religious gatherings being held since 1960's to revive Islamic tenets. It shuns politics and calls for peace. (Photo by A. M. Ahad/AP Photo)

A Bangladeshi Muslim participates in Akheri Munajat, or last prayers, at the conclusion of the Biswa Ijtema or World Muslim Congregation at Tongi, some 30 kms north of Dhaka January 26, 2014. (Photo by Munir Uz Zaman/AFP Photo)

Bangladeshi Muslims board overcrowded trains to return home after attending three-day Islamic Congregation on the banks of the River Turag in Tongi, 20 kilometers (13 miles) north of the capital Dhaka, Bangladesh, Sunday, January 26, 2014. (Photo by A. M. Ahad/AP Photo)

Bangladeshi Muslim devotees arrive on overcrowded trains to attend the Biswa Ijtema or World Muslim Congregation at Tongi, some 30 kms north of Dhaka on January 26, 2014. (Photo by Munir Uz Zaman/AFP Photo)

Bangladeshi Muslim participate in Akheri Munajat, or last prayers, at the conclusion of the Biswa Ijtema, or World Muslim Congregation, at Tongi, some 30 kms north of Dhaka January 26, 2014. (Photo by Munir Uz Zaman/AFP Photo)

A vendor sells paan, a stimulating chewable preparation, as Bangladeshi Muslim devotees try to head to their homes in over-crowded trains after attending three-day Islamic Congregation on the banks of the River Turag in Tongi, 20 kilometers (13 miles) north of the capital Dhaka, Bangladesh, Sunday, January 26, 2014. (Photo by A. M. Ahad/AP Photo)

Bangladeshi Muslim devotees arrive on overcrowded trains to attend the Biswa Ijtema or World Muslim Congregation at Tongi, some 30 kms north of Dhaka on January 26, 2014. (Photo by Munir Uz Zaman/AFP Photo)

Bangladeshi Muslim devotees head to their homes in an over-crowded train after attending three-day Islamic Congregation on the banks of the River Turag in Tongi, 20 kilometers (13 miles) north of the capital Dhaka, Bangladesh, Sunday, January 26, 2014. (Photo by A. M. Ahad/AP Photo)

Bangladeshi railway police try to clear line, as thousands of Bangladeshi Muslims gather to board trains to return home after attending three-day Islamic Congregation on the banks of the River Turag in Tongi, 20 kilometers (13 miles) north of the capital Dhaka, Bangladesh, Sunday, January 26, 2014. (Photo by A. M. Ahad/AP Photo)

Hundreds of Bangladeshi Muslims board a ferry after attending three-day Islamic Congregation on the banks of the River Turag in Tongi, 20 kilometers (13 miles) north of the capital Dhaka, Bangladesh, Sunday, January 26, 2014. (Photo by A. M. Ahad/AP Photo)

Bangladeshi Muslims arrive on an overcrowded train to attend the Biswa Ijtema or World Muslim Congregation at Tongi, about 30 kms north of Dhaka on January 26, 2014. (Photo by Munir Uz Zaman/AFP Photo)

Bangladeshi Muslims pray as thousands of them on overcrowded trains try to return home after attending three-day Islamic Congregation on the banks of the River Turag in Tongi, 20 kilometers (13 miles) north of the capital Dhaka, Bangladesh, Sunday, January 26, 2014. (Photo by A. M. Ahad/AP Photo)

A man jumps from the top of one overcrowded train to another as thousands of Bangladeshi Muslims try to return home after attending three-day Islamic Congregation on the banks of the River Turag in Tongi, 20 kilometers (13 miles) north of the capital Dhaka, Bangladesh, Sunday, January 26, 2014. (Photo by A. M. Ahad/AP Photo)

Bangladeshi Muslims arrive on an overcrowded train to attend the Biswa Ijtema or World Muslim Congregation at Tongi, about 30 kms north of Dhaka on January 26, 2014. (Photo by Munir Uz Zaman/AFP Photo)

A man jumps from the top of one overcrowded train to another as thousands of Bangladeshi Muslims try to return home after attending three-day Islamic Congregation on the banks of the River Turag in Tongi, 20 kilometers (13 miles) north of the capital Dhaka, Bangladesh, Sunday, January 26, 2014. (Photo by A. M. Ahad/AP Photo)

Bangladeshi Muslim devotees head to their homes in an over-crowded train after attending three-day Islamic Congregation on the banks of the River Turag in Tongi, 20 kilometers (13 miles) north of the capital Dhaka, Bangladesh, Sunday, January 26, 2014. (Photo by A. M. Ahad/AP Photo)

Bangladeshi Muslims arrive on an overcrowded train to attend the Biswa Ijtema or World Muslim Congregation at Tongi, about 30 kms north of Dhaka on January 26, 2014. (Photo by Munir Uz Zaman/AFP Photo)