A female suicide bomber hiding among Iranian pilgrims has blown herself up in northern Baghdad, killing at least 35 people and wounding 72 others.

Local authorities say the bomber set off her explosives near the Imam Moussa al-Kadhim shrine in the Kadhimiya neighborhood, as Shi'ites prepared for the upcoming Ashura holiday. The victims included women and children.

In a joint statement Sunday, the U.S. ambassador to Iraq, Ryan Crocker, and the top U.S. general in Iraq, Ray Odierno, strongly condemned the attack.  They said the United States remains as resolute and determined as ever to defeat the enemies of peace. 

Ashura commemorates Imam Hussein, a grandson of the Prophet Muhammad, who died in a seventh-century battle. Ashura observances have been marked by sectarian clashes in recent years.

Also Sunday, the U.S. military transferred control of tribal guards units in Diyala province to the Iraqi government.

The units are made up mostly of Sunni Arabs and former insurgents. U.S. officials credit the group's nearly 100,000 members with helping to drastically reduce the level of violence around the country.

Eventually, the members either will be integrated into the Iraqi military and police, or provided with civilian jobs and training.

The handover is part of the new security deal that calls for U.S. forces to be withdrawn from the country by 2011.

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