"The sender and the Bulgarian side are currently discussing the possibility of transporting the camels ... via the territory of Russia, Belarus and Poland," the border guard officer said.
On Saturday, a truck carrying the camels from the Russian republic of Kalmykia was stopped by Ukrainian customs officials after crossing the Russian border. Customs agents checked all of the documents and cleared the truck containing the animals to leave Russia, but the truck was not allowed into Ukrainian territory.
A Russian customs spokesman said on Wednesday that the animals had been denied entry to Ukraine in connection with laws prohibiting the transit of animals through the country due to concerns over African swine fever.
A truck to transport the animals is expected to leave Bulgaria on Friday.
The animals have had to endure freezing temperatures, although hay and water are being provided.