BAGHDAD (CNN) -- Three Iraq boys were killed in an airstrike in eastern Baghdad on Saturday as they were sifting through trash, looking for stuff to sell, said a 10-year-old boy wounded in the attack.

Ambulances sit damaged after a U.S. attack Saturday near Baghdad's Al-Sadr Hospital.

"I was hit by an American helicopter," Ahmed Yahya said. "I was with a group of about 10 children who were collecting empty soft drink cans in Jamila. We haven't done anything."

U.S. military officials confirmed firing two Hellfire missiles at a rooftop in the vicinity about the same time that the boy said the attack took place. However, they say the only damage U.S. forces saw was to the rooftop.

Another boy said his brother died in the attack.

Dr. Jawad al-Mousawi, chief doctor at Imam Ali hospital in Sadr City, said the hospital received the bodies of three boys and a wounded boy about 2 p.m. He said the hospital saw three other fatalities and treated 23 wounded people from airstrikes and fighting across the city.

An ambulance driver at the hospital said it took three hours to transport the boys because of fighting in the area.

Elsewhere in Baghdad, U.S. soldiers killed five suspected militants and detained 24 others in fighting Friday and Saturday in the city's southern Rashid district.

Earlier Saturday at least 28 people were wounded in a U.S. attack on a building near a hospital in Baghdad's sprawling Sadr City area, an Iraqi Interior Ministry official said.

Employees of al-Sadr Hospital were among the wounded, and the facility's property sustained damage, including to some ambulances, the official said.

In a statement, the U.S. military said the strike targeted "known criminal elements."

"We did hit the target, which was a criminal command and control center, which was near a hospital," the military said, adding that it was assessing damages. Watch scenes of damage near the hospital »

The Interior Ministry official called the attack an airstrike, but the U.S. military said it was a guided multiple-launch rocket system strike. These guided rockets are launched from armored vehicles.

Al-Sadr Hospital is one of the two main medical facilities in the district, where Iraqi and U.S. troops have been battling Shiite militias loyal to radical Shiite cleric Muqtada al-Sadr.

The strike left a large hole in the ground near the hospital, video footage showed. Chunks of concrete and other rubble covered the ground, and car windows were shattered.

The southern portion of Sadr City has been walled off so that U.S. military and Iraqi security forces can control movements there.

Other developments

• Four U.S. Marines were killed Saturday when their vehicle struck a roadside bomb in Iraq's al Anbar Province, the military said. Their names were withheld pending notification of their families.

• Turkey's military said Saturday that it had killed more than 150 Kurdish rebels in northern Iraq in an operation that ended early Friday, according to a statement on the military's Web site. Turkey has been staging attacks against rebels with the PKK, or Kurdistan Workers' Party, in the Qandil Mountain region in northern Iraq. A PKK official said Friday there were no party casualties.

• A roadside bomb exploded Saturday at a traffic patrol in the western part of Baghdad, killing an Iraqi traffic police officer and wounding eight others, including six traffic police officers, a ministry official said.

• Overnight, six people were killed and 25 were wounded in Sadr City, the Interior Ministry said. The U.S. military said it killed six "criminals." On Friday, U.S. forces killed eight suspected militants during 10 hours of fighting in the Shiite neighborhood, a military statement said.

• A U.S. soldier on combat patrol in eastern Baghdad was killed Friday when a roadside bomb struck the soldier's vehicle, the military said. The number of U.S. military deaths in the Iraq war stands at 4,066, including eight Defense Department contractors. E-mail to a friend

All About Sadr City • Iraq War • Baghdad