TRIPOLI, Libya — The sign on the wall reads “Schoolbook Printing and Storage Warehouse,” but the fact that the double gates in the wall have been crudely ripped off suggests that something more interesting might be inside.

It turns out that the only books to be found in any of the three large buildings in the walled compound are manuals — how to fire rocket launchers and wire-guided missiles, among others. The buildings are actually disguised warehouses full of munitions — mortar shells, artillery rounds, anti-tank missiles and more — thousands of pieces of military ordnance that are completely unguarded more than two weeks after the fall of the capital.

Perhaps most interesting of all is what is no longer there, but until recent days apparently was: shoulder-fired heat-seeking missiles of the type that could be used by terrorists to shoot down civilian airliners. American authorities have long been concerned that Libyan missiles could easily find their way onto the black market.

These missiles, mostly SA-7b Grails, as NATO refers to them, have been spotted in Libya before and are well known to have been sold to the government of Col. Muammar el-Qaddafi by former Eastern bloc countries. The evidence at the schoolbook warehouse confirms just how large those quantities were. It also raises questions about how many of them may have been purloined by rebels, criminals or smugglers.