It could be Hamas....but they would be wiped out in retaliation...although they did say they were planning a huge operation.
They also think the US won't act because of the election season...but GWB won't care...if he for some reason loses Nov 2, he will clean up as much as he can before Jan.
The IDF has Assumed Command
02:22 Oct 08, '04 / 23 Tishrei 5765
(IsraelNN.com) The IDF has assumed overall command of the efforts dealing with the attacks in Egypt, rescue of victims, as well as the evacuation of Israelis from Egypt. This has been confirmed a short time ago by spokeswoman Brigadier-General Ruth Yaron.
For what it's worth, Hamas has claimed credit.