Two people were killed and 13 others injured on Sunday morning when two bomb explosions hit Shiite pilgrims during their days-long march to a shrine for a major religious gathering, an Interior Ministry source said.

A roadside bomb explosion struck a group of Shiite pilgrims who were traveling on foot in Baghdad's northern district of Qahira on their way to the holy city of Karbala, 110 km southwest of Baghdad, killing two pilgrims and wounding 11 others, the source told Xinhua on condition of anonymity.

Another roadside bomb went off at the Nahdha area in central Baghdad woxinhuaunding two people, the source said.

In a separate incident, more than five mortar rounds landed on a U.S. base in the Baladiyat neighborhood in eastern part of the capital, the source added, without giving further details about the attack.

Hundreds of Shiite pilgrims are marching from different Iraqi provinces to the holy city of Karbala to commemorate Arbaeen ritual which is the end of 40 days of mourning for Imam Hussein, the Prophet Muhammad's grandson who was killed at the battle of Karbala in 680 A.D. by fellow Muslims who sought to prevent him from becoming the caliph, or Muslim leader, and since then his death became a key moment in the Sunni-Shiite schism.

Major Shiite commemorations have frequently been targeted in the past by suspected Sunni insurgents led by al-Qaida in Iraq in their drive to incite sectarian violence in the war-torn country.

Xinhua News Agency February 8, 2009)