Patrik Stollarz / AFP - Getty Images

Leverkusen supporters show protest cards during the Bundesliga soccer match Bayer Leverkusen vs Hamburger SV in the German city of Leverkusen on December 15, 2012.

Fans of Bayer Leverkusen and Hamburg held black cards and lit flares Saturday as they protested new security measures to be introduced in German soccer stadiums.

German clubs have agreed a toughened set of rules for supporters due to concerns over a rise in violence connected to the sport, Reuters reported on Wednesday.

The Guardian's David Conn reported earlier this month that supporters groups "have interpreted the suggestions ... as a means by stealth to sedate German football's raucous, standing fan culture."

Wolfgang Rattay / Reuters

A fan of Hamburger SV holds a flare during his team's Bundesliga soccer match against Bayer Leverkusen to protest against the so-called "security package" of the German Football League, in Leverkusen on December 15, 2012.

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