Millions of Iraqi and international Shia pilgrims are converging on the southern province of Karbala for the annual Arbaeen pilgrimage, one of the largest religious gatherings in the world. This event, which marks the 40th day of mourning following the martyrdom of Imam Hussein bin Ali, a central figure in Shia Islam and the grandson of the Prophet Muhammad, is expected to draw over 22 million participants this year, according to official reports. The Arbaeen pilgrimage, observed primarily in Shia-majority Iraq and neighbouring Iran, is set to take place on 25 August. Pilgrims from across Iraq…