Originally posted by the Voice of America. Voice of America content is produced by the Voice of America, a United States federal government-sponsored entity, and is in the public domain. Bomb Kills 4 Pilgrims in Northern Iraq as Millions of Shi'ites Observe Ashura VOA News 27 December 2009 Photo: AP A flag bearing the likeness of Imam Hussein flies as Shiite Muslim worshippers gather during the festival of Ashoura, when faithful show their grief over the 7th-century killing of the Prophet Muhammad's grandson, Imam Hussein, in Mosul, Iraq, 27 Dec. 2009. Iraqi officials say a bomb has exploded among Shi'ite pilgrims marking the holy day of Ashura in northern Iraq, killing at least four people and wounding about 20 others. Sunday's blast in the town of Tuz Khormato is the latest in a series of attacks targeting Iraqi Shi'ites in the run up to Ashura. Millions of Shi'ites joined processions across Iraq Sunday, the high point of the 10-day religious observance. Authorities say an estimated three million pilgrims were taking part in the main procession in the holy city of Karbala, home to the shrine of Imam Hussein. Men beat their heads and chests in ritual acts of mourning for the seventh-century killing of the imam, a grandson of the Prophet Muhammad. No attacks were reported in and around Karbala, where authorities deployed an extra 25,000 security personnel to prevent violence. In the days leading up to Sunday, attacks on Shi'ite pilgrims across Iraq had killed at least 20 people and wounded more than 100 others. Sunni militants have targeted Shi'ite observances in Iraq in the past. Former Iraqi leader Saddam Hussein, a Sunni, strictly limited Ashura rituals during his rule. Since his overthrow by U.S.-led forces in 2003, Ashura has become a show of strength for Iraq's majority Shi'ites. Some information for this report was provided by AP, AFP and Reuters. .