Austria marked Tuesday 75 years since German troops crossed the border unopposed on the early hours of March 12, 1938 and "annexed" Hitler's native country into the Third Reich. "Already on the evening of March 11 swastika flags were fluttering over Vienna and other cities, including at police headquarters in Vienna ... even though not a single German soldier had yet set foot on Austrian soil," President Heinz Fischer said at a ceremony in the capital, according to the AFP news agency.