The jump in the use of the bombs, or improvised explosive devices, highlights the more aggressive tactics being employed by militants against U.S. and NATO troops in Afghanistan, USA Today reported Monday.
Some 161 troops from U.S.-led coalition forces in Afghanistan were killed by IEDs last year, more than doubling in 2007 death toll of 75, Pentagon data show.
In Afghanistan, "an emboldened, increasingly aggressive enemy has increased the use of IEDs," Defense Department spokeswoman Irene Smith told the newspaper.
"The trajectory of trends in 2008 has been in the wrong direction," added Michael O'Hanlon, a military analyst at the Brookings Institution. "We're losing the war. This shows a greater capacity on the part of the Taliban and other insurgents to cause more death, destruction and challenges to the legitimacy of the Afghan government."