The death toll in a suicide bombing on Sunday has risen to 40, while about 60 people were wounded in the most serious attack in weeks.

The attack targeted Shiite pilgrims at about 3:00 P.M. (1300 GMT) in the town of Iskandriya, some 50 km south of Baghdad.

"A suicide bomber wearing an explosive vest blew himself up at a procession of Shiite pilgrims were traveling on foot to the holy city of Karbala," an Iraqi Interior Ministry source told Xinhua on condition anonymity, adding women and children were among the casualties.

The US military said the attack took place on a two-lane highway near a residential area where about 42,000 pilgrims had passed through earlier in the day.

Earlier, three pilgrims were killed and 46 others were wounded when a roadside bomb detonated in the morning and was followed by gunfire from unknown gunmen on the highway in Baghdad's southern neighborhood of Doura.

The US military said it responded several grenade attacks in Baghdad against pilgrims.

The Shiite pilgrims were heading to Karbala, some 110 km south of Baghdad, to observe the 40-day Arbaeen festival which remembers the martyrdom of Imam al-Hussein, the grandson of Prophet Mohammad, who was killed in the battle of al-Taf in Karbala in the seventh century.

Sunday's bombing was the severest after two Baghdad markets were under suicide attacks on February 1. At least 65 people were killed and about 150 injured in those two incidents.

(Xinhua News Agency February 25, 2008)