An aerial view of the holy Muslim Shiite shrine of Imam Moussa al-Kazim as pilgrims gather to commemorate his death, in the Shiite district of Kazimiyah, Baghdad, Iraq, Wednesday, May 13, 2015. The anniversary of 8th century Shiite Imam Moussa al- Kazim drew tens of thousands of Shiites from all walks to converge on his golden-domed shrine in northern Baghdad. The pilgrims typically march to the shrine while hundreds of tents are erected to offer them free food, drinks and services. (Photo by Hadi Mizban/AP Photo)

Shiite pilgrims pray at the Imam Mousa al-Kazim shrine to commemorate his death, in the Shiite district of Kazimiyah, Baghdad, Iraq, Wednesday, May 13, 2015. (Photo by Karim Kadim/AP Photo)

An aerial view of the holy Muslim Shiite shrine of Imam Moussa al-Kazim as pilgrims gather to commemorate his death, in the Shiite district of Kazimiyah, Baghdad, Iraq, Wednesday, May 13, 2015. (Photo by Hadi Mizban/AP Photo)

An aerial view of the holy Muslim Shiite shrine of Imam Moussa al-Kazim as pilgrims gather to commemorate his death, in the Shiite district of Kazimiyah, Baghdad, Iraq, Wednesday, May 13, 2015. (Photo by Hadi Mizban/AP Photo)

Shiite pilgrims pray at the Imam Moussa al-Kazim shrine to commemorate his death, in the Shiite district of Kazimiyah, Baghdad, Iraq, Wednesday, May 13, 2015. (Photo by Karim Kadim/AP Photo)

Shiite pilgrims beat their chests as they march towards the Imam Mousa al-Kazim shrine to commemorate his death, in the Shiite district of Kazimiyah, Baghdad, Iraq, Wednesday, May 13, 2015. (Photo by Karim Kadim/AP Photo)

Shiite pilgrims pray at the Imam Mousa al-Kazim shrine to commemorate his death, in the Shiite district of Kazimiyah, Baghdad, Iraq, Wednesday, May 13, 2015. (Photo by Karim Kadim/AP Photo)

Shiite pilgrims pray at the Imam Mousa al-Kazim shrine to commemorate his death, in the Shiite district of Kazimiyah, Baghdad, Iraq, Wednesday, May 13, 2015. (Photo by Karim Kadim/AP Photo)

An aerial view of the holy Muslim Shiite shrine of Imam Moussa al-Kazim as pilgrims gather to commemorate his death, in the Shiite district of Kazimiyah, Baghdad, Iraq, Wednesday, May 13, 2015. (Photo by Hadi Mizban/AP Photo)

Shiite pilgrims pray at the Imam Mousa al-Kazim shrine to commemorate his death, in the Shiite district of Kazimiyah, Baghdad, Iraq, Wednesday, May 13, 2015. (Photo by Karim Kadim/AP Photo)

An aerial view of the holy Muslim Shiite shrine of Imam Moussa al-Kazim as pilgrims gather to commemorate his death, in the Shiite district of Kazimiyah, Baghdad, Iraq, Wednesday, May 13, 2015. (Photo by Hadi Mizban/AP Photo)

An aerial view shows Shiite pilgrims walk towards the festival of Imam Moussa al-Kazim as pilgrims gather to commemorate his death, in the Shiite district of Kazimiyah, Baghdad, Iraq, Wednesday, May 13, 2015. (Photo by Hadi Mizban/AP Photo)

An aerial view of the holy Muslim Shiite shrine of Imam Moussa al-Kazim as pilgrims gather to commemorate his death, in the Shiite district of Kazimiyah, Baghdad, Iraq, Wednesday, May 13, 2015. (Photo by Hadi Mizban/AP Photo)

Shiite pilgrims pray at the Imam Mousa al-Kazim shrine to commemorate his death, in the Shiite district of Kazimiyah, Baghdad, Iraq, Wednesday, May 13, 2015. (Photo by Karim Kadim/AP Photo)

Shiite pilgrims pray at the Imam Mousa al-Kazim shrine to commemorate his death, in the Shiite district of Kazimiyah, Baghdad, Iraq, Wednesday, May 13, 2015. (Photo by Karim Kadim/AP Photo)

An aerial view of the holy Muslim Shiite shrine of Imam Moussa al-Kazim as pilgrims gather to commemorate his death, in the Shiite district of Kazimiyah, Baghdad, Iraq, Wednesday, May 13, 2015. (Photo by Hadi Mizban/AP Photo)