The world’s largest folk festival is officially under way, after Munich Mayor Dieter Reiter tapped the first barrel of beer at noon (1000 GMT) on Saturday to start this year’s Oktoberfest. This means beer can now begin to flow in the many tents pitched on the Wiesn, the festival’s venue. Up to 6 million visitors are expected to flock to this year’s Oktoberfest, which runs until October 6.