A court on the Greek island of Rhodes sentenced two men to prison for espionage for Turkey, according to state television ERT late Wednesday.

The Turkish foreign ministry slammed the decision, claiming that the court “acted with bias.”

A 36-year-old man who worked at the Turkish consulate on the island was sentenced to five years in prison. A second guy, a 53-year-old identified as a former ferry cook, was sentenced to four years in prison and conditionally released, according to ERT.

Both men, who are said to be members of Greece’s Muslim minority, have filed an appeal.

They were detained last year, and reports at the time stated that the man working on the ferry was sending information to the other suspect, including specifics on the whereabouts of Greek Navy ships.

The second defendant was working on a ferry from Rhodes to the Greek island of Kastellorizo, which is located close off the Turkish shore.

Kastellorizo lies in disputed waters that have been a source of escalating tensions between Turkey and Greece.