A Vienna streetcar driver says it was all a joke, but his "Sieg Heil" to passengers has cost him his job — and could potentially land him before a judge.

Officials at Wiener Linien, which operates the Austrian capital's subway, bus and tram system, said Tuesday the man has been fired after uttering the Nazi greeting over the tram's public address system over the weekend.

State-run ORF radio and television said on its Web site that the unidentified 35-year-old made the comment at the end of a a brief statement mentioning that this was his streetcar's last trip on the historic Vienna Ring encircling the city center. Transit authorities ended some streetcar routes on the Ring and changed schedules for others Sunday.

"This is a historic moment and is a day of remembrance of historic events," the Web site quoted him as saying. "Sieg Heil!"

Transit authorities took action after a Jewish newspaper reported the alleged remarks. After some passengers booed — while others laughed — the driver reportedly said: "Can't you take a joke?"

Invoking Nazi symbols and spreading Nazi propaganda are crimes in Austria, which Hitler annexed before World War II, and local news media suggested he might be charged.