US bombers and fighter jets have dropped 40,000lb (18,144kg) of bombs on suspected al-Qaeda targets on the edge of Baghdad in a 10-minute air strike.
The attack on the Arab Jabour district, said to be a safe haven for al-Qaeda in Iraq, was part of the wider Operation Phantom Phoenix launched on Tuesday.
Nine US soldiers have been killed since the start of the operation.
It comes as a World Health Organization survey says 151,000 Iraqis have died violently since the 2003 invasion.
The result is based on interviews with more than 9,000 families across Iraq carried out by the health ministry for the WHO, concentrating on the period from March 2003 until June 2006.
The US military said the air raids on Thursday were precision strikes on three large targets in Arab Jabour, a mostly rural area of palm trees and citrus groves.
A statement said a joint operation between the air and ground troops required "extensive planning to prevent collateral damage".
The BBC's Humphrey Hawksley in Baghdad said there was no word on casualties.
According to the WHO survey, more than half of all violent deaths between 2003 and 2006 were in Baghdad.
The survey authors say they are confident in the general level of accuracy of the answers they received because they had a high response rate, and because the answers from other questions in their survey were consistent with information they already had.
But the authors say 151,000 is not a precise figure, preferring to offer a range of between 104,000 and 223,000.
The best-known casualty tracker is the independent Iraq Body Count which counts only confirmed deaths. The toll it gave for up to June 2006 was under 50,000.
It now gives a range of 80,381 - 87,792