A waiter wearing a face mask serves a table at a restaurant in Vienna

VIENNA, Sept. 6, 2020 (Xinhua) -- A waiter wearing a face mask serves a table at a restaurant in Vienna, Austria, on Sept. 5, 2020. The COVID-19 traffic light system has officially started operation in Austria, the government announced on Friday. Due to the consistently high number of new infections, Austrias three large cities -- Vienna, Linz and Graz -- as well as the Tyrolean district of Kufstein light up in yellow (medium risk), while the rest of the country is designated green (low risk), according to a press conference held by Chancellor Sebastian Kurz and other government officials