Shiite Muslims pray outside the tomb of Shiite Imam Hussein in the shrine city of Karbala, Iraq March 7. Pilgrims gather to attend a festival marking 40 days after Ashura on March 9, the holiest day on the Shiite calendar, commemorating the killing in 680 of Imam Hussein, a grandson of the Prophet Mohammed, by armies of the Sunni caliph Yazid in Karbala.

Seven police deployed to protect pilgrims marching toward city were killed by a car bomb and 12 Iraqi civilians died, one day after suicide bombers killed at least 115 pilgrims in Hilla, south of the capital. Baghdad

Photograph: Ahmad al-Rubaye/AFP/Getty Images