Authorities said Tuesday that they confiscated high-quality forged banknotes made at a printing office at a university in Bulgaria’s capital.

Bulgarian police arrested two people and confiscated a printing machine and equipment for printing currency, as well as large quantities of counterfeit US dollar and euro notes, in a joint operation with the US Secret Service.

“The confiscated currency has a large value. The evidence points to significant criminal activity,” said Sofia police chief Georgi Hadzhiev on Tuesday.

According to the prosecutor’s office, the amount of counterfeit money recovered is $4 million and 3.6 million euros.

The two suspects are believed to be part of a wider criminal organization that traffics counterfeit dollars to Ukraine and euros to Western Europe.