Iraqi officials said a suicide bomber has killed at least 40 people in a strike on Shi'ite pilgrims south of Baghdad, the third such attack in three days.

Iraqi medical officials said most of the victims were women and children.  

Police said a woman blew herself up in a crowd Friday in the town of Iskandariyah, about 40 kilometers south of the capital. They said she hid her explosives under her abaya, the traditional black robe worn by many Muslim women in Iraq.

Police say more than 80 people were wounded in the blast, which targeted Shi'ite Muslim pilgrims making their way to the holy city Karbala for a major religious ceremony.

The attacks this week on Shi'ite pilgrims heading to Karbala for the annual Shi'ite religious ceremony of Arbaeen, which will take place on Monday, echo similar violence during the holiday last year and the year before.  The attacks are also a reminder of the sectarian violence that threatened to tear apart Iraq in recent years.  

On Thursday, Iraqi officials said a bomb blast killed at least eight pilgrims and wounded more than 50 others near Karbala's Imam Hussein shrine.

And on Wednesday, twin bombings killed 16 people near a Baghdad bus station where Shi'ite pilgrims were traveling to Karbala.

The attacks took place despite increased security.  Authorities have set up checkpoints on routes pilgrims are taking into the central Iraqi city.

The Arbaeen ceremony marks the end of the 40-day mourning period following the anniversary of the death of Imam Hussein, grandson of the Prophet Muhammad, in the 7th century A.D.

Some information for this report was provided by AP and Reuters.