Alexander Kots, a Russian journalist and propagandist, claims the explosives used to damage the bridge came from Bulgaria:
https://www.novinite.com/view_news.php?id=217022
Russian war correspondent: The Crimean bridge bomb was placed In foil pallets In Bulgaria
The explosive used to blow up the Crimean bridge came from Bulgaria and was planted in the goods transported by the truck-bomb in Bulgaria. This is what Russian military correspondent Alexander Kots claims in "Komsomolska Pravda".
According to Kots, two trucks were used in the operation to blow up the Crimean bridge. According to him, the cargo consisted of 22 euro pallets with foil, 9 rolls in each, each pallet weighing about 1 ton. The goods arrived by sea in the Georgian port of Poti from Bulgaria. The order was placed in the name of a citizen of Ukraine. It was then loaded onto a truck with foreign license plates and from Poti the truck traveled to Armenia, where it was cleared at customs under the rules of the customs union.
After that, the truck returned to Georgia again, and from there, through the Verkhniy Lars border crossing, entered the territory of Russia. The end point was the city of Armavir, where the pallets were reloaded into another truck and from there to Crimea. Kots hypothesizes that the blast was somehow embedded in the rolls of foil so that they would not be detected by X-ray examination. "And this was done in Bulgaria, which means that in addition to Ukraine, foreign services could have participated in the organization of this terrorist act."
Kots also published photos of the truck with which the cargo left Bulgaria.
On Sunday, the chairman of the Investigative Committee of the Russian Federation reported to President Vladimir Putin that before exploding on the Crimean bridge, the truck bomb passed through the territories of Bulgaria, Georgia, Armenia, North Ossetia and Krasnodar.
The tractor itself with the cargo could not have been in Bulgaria, because the tractor is of the "conventional" type, of the American type with an engine in front of the cab, while in Europe tractors move with a cab above the engine.
The "conventional" ones cannot be driven on the territory of the EU, because with the semi-trailer they exceed the maximum length of 17.60 meters. But they move in Georgia and Russia, and according to truck drivers, the normal practice for such courses is for a semi-trailer truck to drive the semi-trailer to Georgia, and there a local will pick it up.