The couples had just left a Christmas market late Friday when they ran into the seven-strong group and an argument started, according to police. One of the young men hit the 49-year-old victim in the head and he fell to the ground. He died at the scene.
A 50-year-old man who was with him was hit in the face and seriously injured. Their wives were not attacked. The youths fled. Dozens of Augsburg firefighters held a vigil Sunday for their colleague and German Interior Minister Horst Seehofer voiced his dismay at the killing.
Bavaria's state Interior Ministry then announced the arrest of the suspected main culprit and an alleged accomplice. Both were 17 and born in Augsburg; the first had German and unspecified other citizenships and the second was a citizen of an unidentified southern European country.
The ministry said surveillance cameras enabled investigators to identify the suspects. Later Sunday, police said four more suspects had been arrested, the German news agency dpa reported. No details were immediately given on those suspects.