A bomb planted on aparked motorcycle exploded Wednesday on the outskirts of the holy cityof Karbala, killing at least 20 Shi'ite pilgrims and wounding more than100 others amid tight security for the huge religious procession,officials said.
The blast was the latest in a string of attacksthis week that have targeted pilgrims making their way to an importantShi'ite religious observance in Karbala, raising fears of a spike inattacks by suspected Sunni insurgents when the pilgrimage culminatesFriday.
The bomb exploded at about 11 a.m. in an area known asIbrahimia, near the east entrance — one of three — into Karbala, about50 miles (80 kilometers) south of Baghdad, said the official, who spokeon condition of anonymity because he was not authorized to brief media.