RE: Abu Hafs al-Masri Brigades
Al-Qaeda Hunter also offered this background on the Brigades from this link:
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Abu Hafs al-Masri Brigades
The Abu Hafs al-Masri Brigades were formed at some point after the death of Mohammed Atef, a relative by marriage of Osama Bin Laden and at one point the second in command of Al Qaeda. Mohammed Atef, who used Abu Hafs as an alias and was nicknamed al-Masri (meaning "the Egyptian" in reference to his country of birth), was killed by a US Hellfire missile fired from a Predator drone in Afghanistan on November 15th of 2001.
The Abu Hafs al-Masri Brigades appears to be one of the more active offshoots of Al Qaeda. Most of their claims have proved to be unsubstantiated, such as the August 5th bombing of the Marriott Hotel in Jakarta, Indonesia, and the blackout on August 14th of 2003 that struck the north-eastern US. However, they have claimed responsibility for other actions that have not yet been disproven, such as the August 19th, 2003 bombing of UN Headquarters in Iraq and November 15th, 2003 suicide car bomberings of two synagogues in Istanbul, Turkey. They also received worldwide attention when they claimed responsibility for the March 11th train bombings in Madrid, Spain.
http://www.specialoperations.com/Terrorism/Terrorist_Groups/Abu_Haf.htm
And here's more on the Brigades:
http://www.jamestown.org/publications_details.php?volume_id=403&issue_id=3049&article_id=2368408