Security has been tightened in Tongi town near the Bangladeshi capital, Dhaka, where thousands of Muslims from around the world are gathering for the biggest annual Islamic event following the hajj pilgrimage to Mecca.
Bangladeshi authorities say they are expecting some two million Muslims to take part in the event, and have assigned more than 20,000 troops to guard the three-day World Muslim Congregation known as "Biswa Ijtema."
Bangladesh has been on high alert since last August, when 400 almost simultaneous blasts shook the country. The August blasts and subsequent suicide bombings have been linked to an outlawed Islamic group known as Jamaitul Mujahedin.
The group wants to impose strict Islamic law in the Muslim majority but secular country. At least 28 people, including four suicide bombers, have been killed so far in the attacks.