……Since the attacks, a number of organizations have claimed responsibility. The first group to do so was the previously unknown Secret Organisation Group of al-Qaida in Europe. Later, Osama Bin Ladin's second in command, Ayman al-Zawaheri, issued a series of video messages in which he claimed responsibility and praised the attacks for bringing the blessed battle" to the"enemy's land.'' While the targets and methods of the bombings are consistent with previous attacks by al Qaeda and those inspired by the terrorist network, investigators have been unable to verify any group's claim of responsibility for the event.