Soviet Union sending war material towards Bulgaria using warships and not merchant ships according to a CIA report dated 4 September 1953

An item reported that Bulgaria seamen of the merchant fleet thought that a large amount of war material was sent by the Soviet Union towards Bulgaria using especially equipped Bulgarian and Soviet warships but not Bulgarian merchant ships.

Source
The report was published on www.archive.org, document number CIA-RDP80-00810A002200170042-3