I hadn't realized it was a crude bomb, but given what you've said, I think you're right -- that a go ahead signal has been given for the less organized jihadists to do whatever mahem they can do.
post 585 has a description and a link.
http://www.freerepublic.com/focus/f-news/1675804/posts
Then let's se what they've got. Let's see what "jihad" really consists of.