DHAKA, Jan. 11 (Xinhua) -- The first phase of the second largest annual Muslim congregation called "Biswa Ijtema" after holy Hajj will begin Friday morning in Bangladesh capital Dhaka with religious sermons for millions of devotees from home and abroad.

The grand prayer at the congregation at Tongi, some 25 km north of Dhaka, will be held on Sunday, seeking divine blessings and welfare of all mankind.

The second phase of the Biswa Ijtema, which is being held in two phases since 2011 to avoid rush of pilgrims, will begin on the same venue on Jan. 20 and it will conclude with the offering of Akheri Munajat (concluding prayer) on Jan. 22.

To ensure safety and security of the devotees and maintain law and order, thousands of different law-enforcing agencies have been deployed in and around the 60-hectare Ijtema ground, the main venue of the congregation.

Several control rooms, watch towers and a number of close circuit camera have been installed to avert any untoward incidents thereto oversee people's movement.

Local devotees from far and wide of the country are streaming into the Ijtema ground, as buses, trains and all other modes of transport are carrying thousands of people to Tongi.

Organizers say standby airport transport service has been arranged for tens of thousands of devotees expected from about 100 countries.