UEFA president Ceferin calls on Europe to end "cancer" of football violence
After a meeting with Greek Prime Minister Kyriakos Mitsotakis in Athens, Ceferin said that the problem was Europe-wide and cooperation was needed to avoid a repeat of such incidents.
"This is the cancer of football and those are not football fans," Ceferin said. "We came to a position where we have to say enough... we have to stop this.
"Violence and hooliganism are not only a Greek problem," he said adding European countries, institutions and media had to work together to help end football violence.
More than 100 people, most of them Croatian citizens, have been charged with felony and detained pending trial over the clashes that led to 29-year-old AEK fan Michalis Katsouris being stabbed to death in Athens, Greek authorities said.
The pre-trial detentions have led to tension between Greece and Croatia on a political level.
Greek diplomats said the country's foreign minister George Gerapetritis assured his Croatian counterpart that the rights of those detained would be fully respected.
Greece has made repeated efforts to reform soccer, which has been plagued by violence on and off the pitch.
Last year, a 19-year-old fan was beaten and stabbed to death outside Aris Thessaloniki's stadium.
Mitsotakis said that Greece was exploring a further tightening of rules to help end violence at sporting events.