Suspicious packages, including blood-soaked envelopes containing “animal eyes,” have been sent to Ukrainian embassies and consulates in several European cities, the country’s foreign ministry has said, writes CNN.

Kyiv’s embassies in Hungary, the Netherlands, Poland, Croatia, Italy, Austria, and the consulates general in Naples and Krakow, have received such 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 colour and had a corresponding smell,” he said. “We are examining the meaning of this message.”

Friday’s statement came after an explosion 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.

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.

Ukraine has put all of its overseas diplomatic stations under heightened security following the slew of suspicious mail.