He said that according to the latest census, only 1,800 Ruthenians remain in Croatia, of whom about 70 per cent live in Vukovar-Srijem County.
Erdelji underlined that the Ruthenians live in harmony with the majority Croats and other national minorities.
At the observance, Erdelji and the president of the Ruthenian National Council in Serbia, Slavko Rac, signed a cooperation protocol.