British investigators now say that the explosives used in the recent train and bus attacks were "military-grade" (i.e., a professional compound, not a fertilizer mix or some similar homebrew) The article includes much speculation on where they might have gotten it from, checking if anything is missing from quarries, and so on.
Nope, I've got no clue where someone could have gotten their hands on several hundred tonspounds of, say, RDX or HMX. I mean, that stuff is carefully guarded all over the world, and terrorists wouldn't just be able to walk in to a military depot and take it...
Edit: (In response to a comment that should probably stay screened) Oh yes, there are definitely far too many ways to get one's hands on that. I'm just amused (morbidly) that everyone seems to have publicly forgotten about huge volumes of missing HE, and is now remembering that about 60lbs total is enough to wreak pretty extraordinary havoc.
