Forty-five Shiite pilgrims were killed and 110 others were wounded in two suicide bomb attacks in the holy Shiite city of Karbala, south of Baghdad on Thursday, an Interior Ministry source said.

The attack took place in the afternoon when one of the suicide bombers blew himself up among a procession of Shiite pilgrims on the northern entrance of the city of Karbala, the source told Xinhua on condition of anonymity.

Minutes later, another suicide bomber blew himself up among a group of pilgrims in the southern entrance of the city, the source said.

"A total of 45 people were killed and 110 others were wounded by the two blasts," the source added.

Earlier in the day, two Shiite pilgrims were killed and 17 others wounded in two bomb attacks in Baghdad and Iraq's eastern province of Diyala, a provincial police source told Xinhua on condition of anonymity.

The pilgrims were walking on a main road on their way to the holy shrine city of Karbala, some 110 km southwest of Baghdad when the attack took place, the source said.

The attacks against Shiite pilgrims came as tens of thousands of them were marching from different Iraqi provinces to the holy shrine of Imam Hussein in Karbala to commemorate the major ritual of Arbaeen slated for Sunday.

Arbaeen is the end of 40 days of mourning for the Imam Hussein, the Prophet Muhammad's grandson, who was killed at the battle of Karbala in 680 A.D.

Insurgents frequently attacked Shiite pilgrims who perform communal rituals in the Iraqi cities, killing and wounding dozens of them in attempts to provoke sectarian strife in the violence- shattered country.

Violence and sporadic high-profile bomb attacks continue in the Iraqi cities despite the dramatic decrease of violence over the last three years.