Serbian authorities say they are investigating after two U.S.-made Hellfire missiles were found on a passenger flight from Lebanon.
The Serbian public prosecutors' office said on March 14 it was investigating whether the packages contain explosive materials.
In a statement e-mailed to the Associated Press news agency, it said the investigation also focused on where the missiles came from and what their final destination was.
Officials say sniffer dogs found the U.S.-bound missiles on an Air Serbia flight at Belgrade airport on March 12.
The Lebanese Army says the missiles were for training purposes and did not contain explosives. It said it decided to send them back to the American company that produced them.
The AGM-114 Hellfire is a laser-guided missile that can be fired from air, sea, or ground platforms.