WASHINGTON — The deaths of two U.S. soldiers in western Baghdad last week have sparked concerns that Iraqi insurgents have developed a new weapon capable of striking what the U.S. military considers its most explosive-resistant vehicle.
The soldiers were riding in a Mine Resistant Ambush Protective vehicle, known as an MRAP, when an explosion sent a blast of super-heated metal through the MRAP's armor and into the vehicle, killing them both.
Their deaths brought to eight the number of American troops killed while riding in an MRAP, which was developed and deployed to Iraq last year after years of acrimony over light armor on the Army's workhorse vehicle, the Humvee.
The military has praised the vehicles for saving hundreds of lives, saying they could withstand the IEDs, or improvised explosive devices, which have been the biggest killers of Americans in Iraq. The Pentagon has set aside $5.4 billion to acquire 4,000 MRAPs at more than $1 million each, making the MRAP the Defense Department's third largest acquisition program, behind missile defense and the Joint Strike Fighter.
But last Wednesday's attack has shown that the MRAPs are vulnerable to an especially potent form of IED known as an EFP, for explosively formed penetrator, which fires a superheated cone of metal through the vehicle's armor.
Military officials are still trying to determine whether last week's attack is a sign of "new vulnerabilities (in the vehicle) or new (weapons) capabilities" on the part of insurgents, said Navy Capt. John Kirby, a spokesman for Adm. Michael Mullen, chairman of the Joint Chiefs of Staff.
U.S. officials don't know if the EFP that pierced the MRAP was larger, redesigned or a lucky shot from an old one. But explosive experts in Iraq are investigating, said Col. Jerry O'Hare, a military spokesman in Iraq.
The attack comes at a precarious political juncture in Iraq. U.S. officials have accused Iran of shipping EFPs across the border and arming militias. They charge that despite assurances from Iran that it would curtail its shipment of EFPs, new weapons have arrived this year.
So far, military officials in Baghdad don't know whether the EFP used in the attack was Iranian-made or if it was shipped to Iraq this year.
Five of the eight soldiers who've died in MRAPs were killed in April, said Geoff Morrell, a Pentagon spokesman. Earlier in the month, a soldier was killed when an explosive struck an MRAP and it rolled over. Another two died in April when their MRAP rolled over and they drowned, Morrell said.
(Jonathan S. Landay and Warren P. Strobel contributed.)