Shi'ite pilgrims march on their way to Karbala for Arbaeen, in Baghdad, Iraq, Thursday, Jan. 20, 2011. A pair of bombs blasted through security checkpoints ringing Karbala Thursday, Jan. 20, 2011,  and killed at least 50 people, many of whom were Shi'ite pilgrims headed to observe yearly religious rituals. (AP Photo/Khalid Mohammed)

Photo by: Khalid Mohammed

Shi'ite pilgrims march on their way to Karbala for Arbaeen, in Baghdad, Iraq, Thursday, Jan. 20, 2011. A pair of bombs blasted through security checkpoints ringing Karbala Thursday, Jan. 20, 2011, and killed at least 50 people, many of whom were Shi'ite pilgrims headed to observe yearly religious rituals. (AP Photo/Khalid Mohammed)