Egypt: A Small, Freelance Group?

The Egyptian authorities are now saying that the bomb on Sunday was a nail bomb, apparently made with black powder, presumably planted by a small Islamist cell. Assuming this proves to be true, it would be another indication that the major challenge for counterterror operations in the future may not be well-organized networks like al-Qa'ida, but rather small, freelance operations of a handful of people with unsophisticated technologies. A black powder nail bomb may be limited in its lethality, but by striking at the crucial tourist sector, it can have a decidedly asymmetric impact.

Of course, since so far as public announcements indicate the actual perpetrators remain unknown, one assumes these conclusions (which Al-Ahram attributes to "security agencies") are based on the nature of the bomb rather than actually knowing the identities of the bombmakers.

More here, suggesting someone could identify the pereptrators.