Security has tightened at Oktoberfest after a deadly knife attack last month in western Germany, and officials are warning revelers

Munich's Oktoberfest, the world's biggest beer festival, opened Saturday under heightened security following a string of attacks in Germany attributed to jihadists.

Oktoberfest will open after the ceremonial keg-tapping by Munich Mayor when he inserts the tap into the first keg at noon on Saturday.

Strong, amber-colored Marzenbier is the traditional beer served at Oktoberfest in Munich, Germany. But it's now found only in the United States.

The festival takes place in Munich every year, at Theresienwiese, a 100-acre fairground space in the city’s Ludwigsvorstadt-Isarvorstadt district, near the Old Town. Believe it or not, Oktoberfest isn’t actually considered a beer festival in Germany – instead, it’s a folksy celebration popular among families as well as those after a stein or two.