A car bomb has killed at least 20 Shia Muslim pilgrims in the town of al Musayyib, south of Baghdad, as worshippers from around the world thronged Iraq's shrine city of Karbala to finish mourning rituals for a revered figure in Shia Islam.
Thursday's attack came despite a massive security operation mounted to safeguard the millions of pilgrims travelling to and from Karbala for the conclusion of Arbaeen commemorations.
