U.S. troops and warplanes have waged a major attack on the Shiite neighborhood of Sadr City in Baghdad. U.S. officials say at least 32 Iraqi militants have been killed, but Iraqi police say at least nine of the dead are civilians. The Washington Post described the raid as one of the largest in a series of U.S. attacks against Shiite militias. The raid on Sadr City came shortly after Iraqi Prime Minister Nouri al-Maliki left Baghdad for Tehran, where he met with several Iranian leaders. Hundreds of Baghdad residents held protests last night against the U.S. for attacking Sadr City less than 24 hours before the start of a major Shiite holiday. Meanwhile, Iraqi officials have imposed a strict curfew and banned all vehicular traffic in Baghdad until Saturday in an attempt to prevent car bombings during the holiday.