BAGHDAD (AP) -- U.S. forces backed by air strikes raided Sadr City, Baghdad's main Shia district, on Sunday, killing six militants as they targeted a militia leader accused in high-profile kidnappings, the military said.

Iraqi officials said at least 13 people were killed, including children, and dozens more were wounded. Relatives gathered at the Imam Ali hospital as the emergency room was overwhelmed with bloodied victims and the dead were placed in caskets covered by Iraqi flags.
The bodies of two toddlers, one with a gouged face, were swaddled in blankets on the floor of the morgue. Their shirts were pulled, exposing their abdomens. A diaper showed above the waistband of the shorts of one of the boys, according to Associated Press Television News video.
Iraqi police and hospital officials said at least 13 people were killed, including a woman and three children, and 52 were wounded during the 5 a.m. raid in the sprawling district.
Several houses and shops, including a bakery and a large generator, were damaged in the fighting, which witnesses said lasted two hours.
An initial military statement e-mailed to The Associated Press said the raids were targeting ""criminals believed to be responsible for the kidnapping of coalition soldiers in November 2006 and May 2007.""
A later release said U.S. troops, acting on intelligence, raided a number of buildings in an operation targeting a rogue Shiite militia leader specializing in Iranian-funded kidnappings.
Ground forces called in air support after they came under fire from machine guns and rocket-propelled grenades from nearby buildings, according to the statement, which added that the troops were hit by a roadside bomb as they left the area. ""Initial reports indicate that no civilians or Coalition forces were killed or injured in the operation,"" the military said. ""An estimated six criminals"" were killed, the military said, although the statement did not make clear if they died in the fire fight or an air strike.
The military said it was targeting a member of a breakaway faction of the Mahdi Army militia that is nominally loyal to Muqtada al-Sadr. The anti-American cleric has called on his fighters to stand down.
At the Imam Ali hospital, a local resident who goes by the name Abu Fatmah said his neighbor's 14-year-old son, Saif Alwan, was killed while sleeping on the roof, wearing a white robe. Abu Fatmah said many of the casualties were people sleeping on the roof to seek relief from the hot weather and lack of electricity. ""Saif was killed by an air strike and what is his guilt? Is he from the Mahdi Army? He is a poor student,"" Abu Fatmah said.
An uncle of 2-year-old Ali Hamid said the boy was killed and his parents seriously wounded when heavy gunfire from a helicopter struck the wall and windows of their house as they slept indoors. APTN video showed a U.S. helicopter flying over the area while black smoke rose into the sky.
Other footage showed three bloodied boys sitting on hospital tables and an elderly man being treated for a head wound. Mourners tied wooden coffins onto the tops of minivans with as smoke rose in the background.