US and Iraqi forces have battled for a second day with militiamen in Diwaniyah, south of Baghdad.
The US military says American aircraft attacked insurgents who were using shoulder-fired rocket-propelled grenades. It says one militiaman was killed.
The security operation is aimed at disrupting activities of Shi'ite militiamen.
In other news, Iranian media reports say an Iranian diplomat who was freed this week, two months after being kidnapped in Baghdad, alleges he was tortured by American intelligence forces (the CIA) during his detention.
The United States has denied any involvement in the abduction of Jalal Sharafi, the second secretary at the Iranian embassy in Baghdad.
Iraqi Foreign Minister Hoshyar Zebari, meanwhile, says a ministerial meeting with Iraq, its neighbors and world powers will be held in Egypt,in the resort town of Sharm el-Sheik) in May.
Separately, the US military says a raid this week on a Sunni political party safe house in Baghdad netted a cache of explosives and illegal weapons.
Officials say 14 people were detained. They were identified as the personal security detachment for an unidentified Iraqi parliamentarian.
Also, the military says Iraqi forces, supported by American troops, raided a mosque in Musayyib and detained two people. It says the search was based on intelligence reports of terrorist activity.
It did not elaborate, but said any building used for criminal activities forfeits its protected status under international law.
The military also said two American soldiers were killed Friday in separate roadside bombings in Baghdad.