The three-day Biswa Ijtema, the second largest Muslim congregation after the hajj, begins on the bank of river Turag at Tongi on Friday.
Thousands of pilgrims from home and abroad thronged the bank of river Turag to join the Biswa Ijtema, also called the World Congregation of Muslims.
Around two million devotees including one lakh women are expected to participate in the congregation.
Around 9,000 foreign devotees from 27 countries have so far arrived at the Ijtema site, said the organisers.
The event will start formally with religious sermon after Fazr prayers on Friday.
Around 20-25 lakh people are expected to attend the Juma prayers on the premises.
The Tablig-e-Jamaat has been organising the gathering since 1976.
Meanwhile, multi-tier security measures have been taken up in and around the venue to avert any possible threats from militant groups and subversive activities of different quarters.
Around 18,000 security personnel from different agencies and several hundred plainclothes law enforcers will vigil the area.
Rab Director General Hasan Mahmud Khandaker inaugurated its control rooms and CCTV at the Ijtema ground on Wednesday.
He said around 18 control rooms have been set up at the venue. Rab will monitor the Ijtema site through 60 CCTVs.
He also said around 800 Rab men divided into five groups will be deployed for 24 hours in the Ijtema ground to ensure security.
Besides, helicopters, speedboats and pickup vans will continue patrolling in around the area.
As part of a special traffic system the Police Headquarters has imposed a ban on traffic movement on some specific roads in and around the area from 6:30pm on Saturday to 6:30pm on Sunday.
No vehicles except those carrying air passengers and aircraft crew, fire service vehicles and ambulances will be allowed to move from Dhour bridge in Tongi to Pragati Sarani via Abdullahpur in Uttara and from Tongi bridge to Gazipur Square.
Tags: bangladesh, ijtema, muslim, religion