Worshippers gather outside Imam Hussein shrine, seen in the background, to mark the Muslim religious tradition of Ashura, an important period of mourning for Shia's in Karbala.—Photo by AP

A Turkish girl holds a chain as she mourns during an Ashura procession in Istanbul.—Photo by Reuters

Supporters of the Supreme Islamic Iraqi Council wave Iraqi national flags during an Ashura gathering in Baghdad, Iraq.—Photo by AP

Children re-enact the role of companions to Imam Hussein during the battle of Karbala, at the Imam Moussa al-Kadhim shrine during Ashura in Baghdad, Iraq.—Photo by AP

Iranian women light candles during the "Chehel Manbar" (Forty Pulpits) ritual a day before Ashura, in the city of Khorramabad.—Photo by AFP

Muslims pray at the shrine of Imam Hussein in Karbala during Ashura.—Photo by AFP

Mourners gather outside the shrine of Imam Abbas early in Karbala during Ashura.—Photo by AFP

Turkish women mourn during an Ashura procession in Istanbul.—Photo by Reuters

Yemeni women mourners march during Ashura in Sanaa.—Photo by AFP

Smeared with mud, a mourner takes part in a parade in preparation for the peak of the Ashura ceremony, near the shrine of Imam Hussein.—Photo by AFP

Mourners practice religious rituals in preparation for the peak of the Ashura ceremony in Karbala.—Photo by AFP

A Shia Muslim pilgrim waves a huge flag at the Imam Hussein shrine during a ceremony marking Ashura in the holy city of Karbala.—Photo by AFP

Shia Muslim pilgrims gather at the Imam Hussein shrine during a ceremony at the start of Ashura in the holy city of Karbala some 80 kilometers southwest of Baghdad.—Photo by AFP