Why Were Hellfire Missiles Shipped From Beirut to Portland (and found in Serbia) in Coffins?

Something very strange is going on with a pair of Hellfire air-to-ground training missiles. Loaded onto a civilian airliner in Beirut, Lebanon, their paperwork said the final destination was Portland, Oregon. But before they could get there, the plane stopped in Belgrade, Serbia, for reasons that aren’t entirely clear right now, where Serbian police and canines sniffed them out. So what the heck is going on here?

link.