Shia pilgrims walk in Baghdad on Sunday. Fifty-four people died Monday after a suicide bomber detonated an explosive belt while walking among pilgrims in northern Baghdad. (Karim Kadim/Associated Press)

Fifty-four people died on Monday after a female suicide bomber walking among Shia pilgrims in northern Baghdad detonated an explosive belt, an Iraqi police official reported.

The official said the bomber struck in the Shia Muslim district of Shaab, and about 117 people were wounded, with 18 women and 12 children are among the dead.

A hospital official confirmed the casualties. Both officials spoke on condition of anonymity because they were not authorized to talk to the media.

Maj.-Gen. Qassim al-Moussawi, Baghdad's top military spokesman, said 19 people were killed and 80 wounded.

Conflicting casualty counts are common in the aftermath of an attack.

Insurgents have routinely targeted pilgrims in Iraq. This week, hundreds of thousands of Shias are heading to Karbala, southwest of Baghdad, to mark the end of 40 days of mourning following the anniversary of the death of a revered Shia figure.