Iraqi Shi'ite Muslims commemorate Ashoura in Kerbala, southwest of Baghdad November 4, 2014. A gathering of millions of Shi'ite Muslims at shrines and mosques across Iraq for the Ashoura religious commemoration passed without any major attacks on Tuesday, under tight security imposed for fear of Islamic State bombers. Ashoura commemorates the death of Imam Hussein, grandson of Prophet Mohammad, who was killed in the seventh century battle of Kerbala. The signs read, "God avenge Hussein". REUTERS/Ahmed Saad (IRAQ - Tags: CIVIL UNREST POLITICS RELIGION)