They looked like they could have been sisters--young women, with the same brown tint to their straight hair, round, smooth cheeks. Both were decapitated just under the chin but their faces were eerily intact, almost serene. They were, according to the U.S. commander who showed their photos, unwitting suicide bombers sent by Al Qaeda in Iraq. Apparently walking between blast walls meant to prevent car bombs, they shook Baghdad Friday with bombs in two open-air markets about 10 minutes apart. And, according to Iraqi officials, both women had Down's Syndrome. The theory is that they were tricked into carrying the explosives--one in a suicide vest and the other in a backpack supplemented with ball bearings the size of a fingertip.

Maj. Gen. Jeffrey Hammond, commander of U.S. forces in Baghdad, made sure to stand away from cameras at the end of a morning press briefing Saturday and showed two photos to a few reporters huddled around him. He said that out of respect to the families of the bombers, he would not show them publicly. "Judge for yourself," he said when asked if the women were related, but he said they looked remarkably similar and "there are some indications they were mentally handicapped."

The photos showed two women with narrow eyes (open) and broad noses, unusual features for Baghdad though not conclusive proof of mental disability. "The two women were used because they don't understand what was happening and they were less likely to be searched," Hammond said. Some reports stated that one of the women was known in the pet market she blew up as a cream seller with developmental disabilities. Women and teenagers have been used to carry bombs before.