38 pilgrims martyred outside Kazmain shrine in Baghdad

The blast occurred at a checkpoint outside the Imam Moussa al-Kadhim shrine in Kadhimiya, a mainly Shi'ite area of Baghdad, as Shi'ites prepared for the Ashura holiday this week to mark the death of Hussein, the grandson of the Prophet Mohammad.

Twenty-five people, including women and children, were killed in a blast at a taxi and bus station in the same neighborhood on December 27.

The attack took place a few days after U.S. forces in Iraq came under Iraqi mandate in accordance with a new bilateral pact that will require the withdrawal of the 140,000 U.S. troops by the end of 2011.

As the United States reduces its activities, Iraqi forces are assuming greater responsibility for security. Violence has dropped dramatically across Iraq, but militants continue to carry out suicide bombings such as the one that shattered the calm in Baghdad on Sunday and other attacks regularly.

Hundreds of thousands of Iraqi Shi'ites will visit the holy city of Kerbala, 80 km (50 miles) southwest of Baghdad throughout the Ashura week to mark the death of Hussein, in one of the most important events in the Shi'ite calendar.