Soccer fans in Croatia have threatened the country's Jews and Serbs with “extermination."

In a letter signed by fans of Hajduk Split, a leading Croatian soccer team and delivered to a church in Zagreb,  the document used Nazi slogans such as "Jews out" and warned both groups to "Ask yourself if these are your last days. We are going to exterminate you all.”

Church officials said they have informed police and that an inquiry is under way to identify the authors of the threat.