(CNN) Ukraine's foreign minister has accused Russia of being behind a series of more than a dozen letters containing explosives or animal parts that were sent to Ukrainian diplomats around the world.
"This campaign is aimed at sowing fear," Dmytro Kuleba told CNN's Matthew Chance in an exclusive interview in Kyiv on Friday.
When asked who he thought was behind the letters, Kuleba told CNN, "I feel tempted to say, to name Russia straight away, because first of all you have to answer the question, who benefits?
"Maybe this terror response is the Russian answer to the diplomatic horror that we created for Russia on the international arena, and this is how they try to fight back while they are losing the real diplomatic battles one after another."
He said he thought that Russia was either directly responsible, or someone "who sympathizes [with] the Russian cause and tries to spread fear."
"The conclusion will be made by investigators, but I think these two versions make most of the sense."
Russian foreign ministry spokesperson Maria Zakharova sent CNN a single word comment in response to Kuleba's claim: "psycho."
There have been 17 cases of embassies receiving either letter bombs, false bomb letters, or letters containing animals parts, like the eyes of cows and pigs, Kuleba added.
CNN was shown an image of one of the letters containing what officials said was the eyeball of a pig inside a padded envelope.
"It started with an explosion at the embassy of Ukraine in Spain," Kuleba said. "But what followed this explosion was more weird, and I would even say sick."
Kuleba was referring to an explosion that occurred on Wednesday at Ukraine's embassy in Madrid, injuring one Ukrainian employee who was handling a letter addressed to the country's ambassador to Spain. Spanish officials said Thursday a letter bomb was also sent to the country's prime minister last week and another to the US embassy.
Kyiv's embassies in Hungary, the Netherlands, Poland, Croatia, Italy, Austria, and the consulates general in Naples and Krakow, have also received suspicious packages, Oleh Nikolenko, spokesperson for the Ministry of Foreign Affairs of Ukraine, said Friday on Facebook.
The packages were "soaked in a liquid of a characteristic color and had a corresponding smell," he said. "We are examining the meaning of this message."
Ukraine has put all of its overseas diplomatic stations under heightened security following the slew of suspicious mail.
The Ukrainian Consulate in Brno, a city in the southeast of the Czech Republic, was briefly evacuated on Friday after receiving a suspicious package containing animal tissue, Czech police added in a tweet on Friday.
Kuleba earlier urged foreign governments to guarantee maximum protection of Ukrainian diplomatic institutions in accordance with the Vienna Convention on Diplomatic Relations.
In addition to the suspicious packages, Nikolenko said the entrance to the Ambassador's residence in the Vatican was vandalized and the Ukrainian Embassy in Kazakhstan received a report of a bomb threat, which was later not confirmed.
Nikolenko also stated that the Ukrainian Embassy in the United States received a letter with a photocopy of a critical article about Ukraine. Most of the envelopes were sent from within Europe, he added.
Czech police tweeted that the consulate in Brno and its immediate surroundings, including a kindergarten, were evacuated Friday. After investigating the package, the police said it did not contain any explosives, adding that they had no information to indicate people at the consulate or its vicinity were in any danger.
"Initial analysis suggest the package contained animal tissue. A detailed analysis of will be conducted in laboratories now," the police tweeted.