A series of bomb blasts in Baghdad has killed at least 17 people, while the U.S. military announced the deaths of four more American troops.
Iraqi officials say two car bombs went off almost simultaneously in the predominately Shi'ite Karrada district on Monday, while another car bomb blast struck near the heavily-fortified Green Zone.
Deadly blasts also occurred in a square in central Baghdad and on a minibus in the capital.
The U.S. military says a Marine was killed Saturday in combat in al-Anbar province, and roadside blasts killed three other U.S. troops over the past few days in Baghdad and south of Samarra.
The continued violence comes as Iraqi officials prepare to host a meeting Tuesday between U.S. and Iranian officials on the Iraq security situation.
The United States has accused Iran of supporting Shi'ite militias in Iraq -- a charge Iran denies. The United States and Iran held ambassador-level meetings in May in their highest-level contacts in nearly 30 years.