Details from a secret meeting between top Iranian and Iraqi officials signal Iran's aim to 'stop arming' militias.
A cease-fire deal between Mr. Sadr's representatives in the Iraqi government and members of the leading Shiite bloc aims to end weeks of fierce battles in Sadr City.
A rare daytime US airstrike in Sadr City on Thursday came as residents said that soldiers were warning them to leave parts of the district, which is a bastion of support for the anti-American cleric Moqtada al-Sadr.
The US military in Iraq says Iran continues to aid militants, but Iraqis now say that they want their own evidence.
At least 47 US soldiers were killed in Iraq in April, making it the deadliest month since September. Many of the casualties are a result of the recent assault on the Mahdi Army.
As US troops draw down, Iraqi forces are taking the lead. Reviews so far are mixed.