Washington ? The number of crude roadside bombs in Afghanistan has doubled in the past year, prompting U.S. officials to rush billions of dollars of new protective gear to troops and double the number of road-clearing teams.

The campaign against the deadly devices, described Thursday by senior officials, follows Pentagon warnings of an increase in casualties in the months to come. President Barack Obama has ordered the deployment of more than 30,000 troops to Afghanistan, and already, more U.S. deaths have accompanied the rise in forces.

Twice as many troops died in the first three months of 2010 compared to the same period last year. The majority of all American deaths and injuries in Afghanistan are believed to have been a result of improvised explosive devices, or IEDs.