Baghdad ? A woman hiding among Iranian pilgrims with a bomb strapped under her black robe killed more than three dozen people Sunday outside a Baghdad mosque during ceremonies commemorating the death of one of Shiite Islam’s most revered saints.

The suicide attack, the most recent in a series that has killed more than 60 people in less than a week, was the latest to mar the transfer of many security responsibilities from the U.S. military to Iraqi forces.

Iraqi security forces have deployed thousands of troops in Baghdad and in the Shiite holy city of Karbala, just south of the capital, to safeguard against attacks during the ceremonies. Attacks by al-Qaida in Iraq, Sunni insurgents and even a Shiite cult have killed hundreds of people in recent years.

The attack in Baghdad’s northern Shiite neighborhood of Kazimiyah, which wounded at least 72 people, comes two days after a suicide bomber slipped into a luncheon at a tribal leader’s home south of Baghdad and killed at least 23 people. More than a dozen other people have died in other attacks since New Year’s Day.