Jan. 10 (Bloomberg) -- The U.S. dropped 20 tons of bombs on a Baghdad suburb in the first 10 minutes of an air strike the military said was aimed at dozens of al-Qaeda targets.

Two B-1 bombers and four F-16 jet fighters attacked Arab Jabour, southeast of the capital, in the third day of Operation Phantom Phoenix, a nationwide assault on al-Qaeda's Iraq branch, the military said today in an e-mailed statement.

``This is this is largest aerial bombing we have conducted in Iraq in at least a year,'' a military spokesman, Major Winfield Danielson, said in an e-mailed statement. Some 40 al- Qaeda positions were hit in the strike, the military said.

The U.S. operation follows a report last month in which the military concluded that al-Qaeda in Iraq is trying to counter a growing tribal movement of Sunni Muslims, the Awakening, which is opposed to Osama bin Laden's terrorist network.

Casualty figures and details of damage weren't immediately available, a spokesman for Iraq's government, Ahmed Shames, said in a telephone interview from Baghdad. The area that was bombed isn't densely populated and consists mainly of date palm forests, he said. The Iraqi government criticized the U.S. last year over air raids against al-Qaeda that left civilians dead.

The first of the U.S.-backed Awakening groups was formed last year in the western province of al-Anbar. Since then, similar groups have sprung up across Iraq and have been targeted in attacks authorities have blamed on al-Qaeda.

The latest strikes are ``aimed at flushing out remaining al- Qaeda extremists operating in the southern Arab Jabour area, and to create conditions for improved security,'' the military said.

Nine U.S. soldiers have been killed since the start of the campaign, the military said. Six died yesterday in a house booby- trapped with a bomb in the northeastern Diyala province and three others were shot dead northwest of Baghdad the previous day.

Before the latest casualties, some 3,912 U.S. personnel had died in Iraq, of whom 3,183 were killed in action. More than 28,800 were wounded, 12,918 of them so seriously they couldn't return to duty, according to the Defense Department Web site.

Last Updated: January 10, 2008 11:20 EST