Romanian military authorities are investigating the theft of missile warheads from a train carrying military equipment from Romania to Bulgaria.

Railway workers noticed Saturday the seals of a railway car were broken when the train arrived in the town of Giurgui (Romania), near the border with Bulgaria. An investigation showed that four boxes of military equipment, containing a total of 64 warheads, were missing.

Sources say the components are not dangerous on their own and American cable channel CNBC reported they contained no explosives.

Bulgaria and Romania are members of the NATO military alliance and the European Union.