Over 90 football fans from Croatia appeared before prosecutors in Athens on Wednesday who are investigating clashes between Dinamo Zagreb and AEK Athens fans in which a Greek man was stabbed to death.
What do we know about the stabbing incident?
Another 10 people were injured in the incident, four of whom remain hospitalized.
Reports said DNA samples were taken from 94 people.
Between 150 and 250 fans of Dinamo Zagreb traveled to Athens for Tuesday's Champions League third round qualifier.
The clashes occurred outside the AEK's arena after Dinamo's training session ended.
Video of the riot showed dozens of men wielding bats and iron bars running past the stadium.
Six Croatian citizens were arrested after attempting to leave Greece, and law enforcement was searching for another 50 people.
The game was postponed by the ruling body UEFA and rescheduled for August 19.
Outside the arena, fans set up tributes to the man who was killed, identified as Michalis Katsouris from a town near Athens.
What did officials say about the clashes?
A vice president of the European Commission, Margaritis Schinas, condemned the "horrible violence.
"(There is) no place for violence and hooliganism in European football," he said.
Greek Public Order Minister Giannis Oikonomou said the police made "tragic errors" in failing to act on information that clashes were likely.
He has dismissed calls from opposition parties to resign and suspended seven police officers.
The AEK arena says it called on UEFA to impose "immediate and severe punishment" on Dinamo Zagreb.
"The question that torments our fans is one that we described from the outset and that also torments us: How is it possible that following the brutal murder of Michalis by a gang of vicious criminals from Croatia, for AEK Athens to enter the field and play against this team?" AEK said.
"Will any of his killers be in the stands?" he added.
