I'm pretty sure that American authorities are trying to hunt down whoever detonated Claymore mines at the finish-line of the Boston Marathon yesterday.
One Indian paper had an account yesterday from an Indo-American special forces vet who ran the race and was at the scene shortly after the bombs/mines went off/detonated. He described multiple amputations, severed legs everywhere, and how he had personally placed tourniquets on six or seven wounded runners.
Another account described small ball-bearings littering the blast site.
These are the hallmarks of the U.S. military's Claymore mine. Small, compact, easily brought onto a site like this, easy to deploy, easy to conceal, directional (safe for the user standing behind it) and offering the capability for remote, command detonation. Placed close enough to a group of runners, each Claymore would blast about 700 small (1/8"), steel balls into the victims' legs. This is the same size Boston doctors report finding in the victims.
Boston Marathon, Boston Tea Party, American tax filing day and an explosive device with the hallmarks of an American military weapon.
How many Claymores have gone unaccounted for since VietNam?