Also, in one of the articles the FBI said there was also another unidentified item in addition to the wires and magnet.
http://www.dawn.com/2004/08/08/top6.htm
"Investigators said the device weighing 1-2kg was locally made and was fitted with a half-an-hour timer. The bomb had a magnet attached to it, they added."
magnet, wire... all he needs is a battery and he could fashion an electric motor - or, perhaps, an improvised electromagnetic pulse weapon.
ok... probably not enough power in a portable battery to make an electromagnetic pulse, but certainly enough to possibly be a "trigger" device. Magnet, wire and ... undisclosed third item.
FWIW. BTW, I did not do well in science in school. LOL.