Police in the Bavarian city of Weiden said Friday the 45-year-old man confronted his neighbors during Thursday's Netherlands-Cameroon World Cup game wielding the ax.
They said he was so sick of the constant buzzing and honking from the vuvuzelas since the tournament began that he screamed: "I will kill you," and then returned home.
German authorities took the U.S. Army civilian employee into custody and turned him over to U.S. military police. The military says he has been released and the matter is in German hands.
Prosecutors are investigating whether to charge the man, whose name was not released, with making a threat and slander for allegedly calling his neighbors names.
The cheap, yard-long vuvuzela trumpets have become a side story of the World Cup in South Africa, where their buzzing has been the backdrop to every match.
Players have been criticizing the noise because they find it difficult to take advice from the bench, and visiting fans have no chance for community singing amid the noise.
A French cable TV channel even offers vuvuzela-free broadcasts for all World Cup matches, with the trumpets digitally tuned out.
Defenders include FIFA President Sepp Blatter, Nobel Peace Prize winner Archbishop Desmond Tutu - and masses of South African football fans.
The trumpets were first produced and marketed in 2001 by South African Neil Van Schalkwyk, who still owns the rights to the vuvuzela name. His latest innovation is to sell each with a pair of earplugs included.
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