U.S. commanders in Iraq are concerned that Shiite insurgents are using a new type of high-powered homemade weapon that uses rockets made in Iran and elsewhere.  In the most recent attack, on Tuesday in northeastern Baghdad, an Iraqi soldier and a U.S. soldier were wounded.  VOA's Al Pessin reports from the Pentagon.

The U.S. military calls the weapons Improvised Rocket-Assisted Munitions (IRAM).  They are propane gas tanks loaded with explosives and lashed to rockets.  Several IRAMs can be packed in the back of an open truck, and launched by remote control.  

One report refers to them as flying roadside bombs, a reference to another relatively crude but highly effective insurgent weapon that has been the leading cause of death among U.S. and coalition troops in Iraq.

"It does concern us," said Major General Michael Oates.  "It is a home-made, multiple-launch rocket system.  And it is very dangerous."

Major General Michael Oates is commander of U.S. and coalition forces in central Iraq, south of Baghdad.  He is concerned even though he has not seen any IRAMs in his area.  The new weapons have so far only been found in Baghdad, where the U.S. military says they have been used by Shiite militias affiliated with Iran, and often powered by Iranian-made rockets.  

But Major General Oates says he does not know for sure whether Iran is providing the material, technology or training for the IRAMs.

"I'm not prepared to state that it's Iranian-made or Iranian-influenced," he added.  "I don't have any information that would lead me to believe that.  It is an improvised explosive, therefore it's not manufactured the way it is employed.  So, somebody is having to train someone to modify this weapon system.  Where that training is coming from, I just don't know the specifics on right now."

U.S. officials have accused Iranian agents of providing equipment and training for high-powered roadside bombs that have killed several U.S. troops.  The Iranian government has denied the charge, even though Iranian operatives have been captured inside Iraq allegedly working on the project.

The Improvised Rocket-Assisted Munitions have been launched into several small American bases, killing three U.S. troops and wounding 15.  But the most deadly IRAM incident involved an aborted attack in early June, in which several of the bombs exploded prematurely, killing 16 Iraqi civilians and two attackers.

In a VOA interview, the spokesman for coalition forces in Baghdad, Lieutenant Colonel Steve Stover, says the IRAMs first appeared late last year, and there have been fewer than 10 such attacks.  He says that's far fewer than attacks by roadside bombs, car bombs, snipers, mortars or conventional rockets.

"The IRAM itself, much like those other weapons systems, is something that we're trying to stay one step ahead of," he explained.  "So, what we're trying to do is find the networks that are making these things.  There is an award for it, that leads to the cell leaders or the people who are making the devices."

Lieutenant Colonel Stover says the military is also taking steps to defend against the new weapons, but he would not provide details.  

He says the rocket-propelled bombs are difficult to hide, because they are launched on rails that often stick out the back of the trucks where they are mounted.  He says they are shot high into the air, but only travel a short distance.

"It's a home-made system," he noted.  "It's something that somebody was taught to make.  I mean, I'm not saying it's a very extremely crude device, but if you take a rail, you put that in the back of a truck, you put a rocket on it and you light a fuse.  It depends on how high you put the rail, that's how high it's going to go."

Lieutenant Colonel Stover says while many of the rockets used in IRAMs were made in Iran, the military has found some that were made in Russia and China.