Security has tightened at Oktoberfest in the wake of last month’s deadly knife attack in Solingen in western Germany, and officials warned revelers to expect longer lines at entry points as metal detectors will be deployed for the first time in the Bavarian beer festival’s 189-year history.

Authorities say there are no specific threats to the world’s largest folk festival, which begins Saturday with the traditional keg-tapping in Munich and runs through Oct. 6. Some 6 million participants, many wearing traditional lederhosen and dirndl dresses, are expected over the course of the event.

The stepped-up security comes after an Aug. 23 attack in Solingen that left three dead and eight wounded. A 26-year-old Syrian suspect was arrested. He was an asylum-seeker who was supposed to be deported to Bulgaria last year but reportedly disappeared for a time and avoided deportation. The Islamic State militant group has claimed responsibility for the violence, without providing evidence.