Iraqi police say a suicide truck bomber has killed at least 15 people outside Ramadi.
They say the blast wounded at least 25 other people.
Earlier on Tuesday, an insurgent group linked to al-Qaida in Iraq claimed responsibility for a Monday bombing that killed nine American soldiers in one of the worst attacks on U.S. ground forces since the 2003 invasion.
The group Islamic State of Iraq made the claim in an Internet statement. Twenty other U.S. soldiers were wounded in the attack near Baquba.
In other developments, gunmen dressed as Iraqi army troops raided a village near Baquba today, killing six people and burning several homes.
In Baghdad, two bombs near the Iranian embassy wounded four people.
Separately, the U.S. military in Iraq says coalition forces have detained 10 suspected terrorists and discovered a weapons cache in operations in Baghdad and Fallujah.
Baquba is the capital of Diyala province where U.S. and Iraqi forces have been battling Sunni insurgents and al-Qaida in Iraq terrorists.