Airborne bomb hits U.S. outpost in Iraq

BAGHDAD — U.S. troops stationed at an outpost in southern Iraq heard a chilling whistle, and then a 60-pound airborne bomb punched through a concrete blast wall and sent shrapnel flying, wounding three Americans.

Explosions are commonplace in Iraq, but this was no ordinary attack. The U.S. military said Friday that militants who launched the Jan. 12 attack on a joint U.S.-Iraqi compound used an unusual weapon called an IRAM, for Improvised Rocket-Assisted Munition. Sometimes called flying IEDs, IRAMs are a potentially deadlier incarnation of the garden-variety Improvised Explosive Devices in Iraq and Afghanistan — they're short-range projectiles that catapult toward unsuspecting targets.

Two IRAMs flew into the outpost in the city of Amarah in a puzzling reappearance of a weapon that's been used only 14 times since the U.S. invaded Iraq in 2003, according to the U.S. military. Most of the earlier attacks occurred in eastern Baghdad more than 18 months ago, at the height of violence related to Shiite Muslim militias. The more recent attacks, however, were launched in southern Iraq's Maysan Province, which borders Iran.

In the most recent incident, only one of the IRAMs exploded, leaving a 12-foot crater in the ground, said Maj. Myles Caggins, a spokesman for the 4th Brigade of the Army's 1st Armored Division.

The other was a dud that's now being investigated by American and Iraqi forensics teams to determine its components and origins. Previous IRAMs have been linked to the Mahdi Army of volatile Shiite cleric Moqtada al-Sadr and other Iranian-backed militias in Iraq.

"Violent Shiite extremist groups typically receive influence from Iranian origins," Caggins said, noting that so far there's no direct evidence that ties the latest attack to Iran. "The Iraqi police we advise are aggressively seeking to root out these networks of terrorists, smugglers and financiers who import and assemble these weapons."