A 29-year-old Greek fan has died following a night of violence among supporters of AEK Athens and Dinamo Zagreb.
The two sides were due to meet tonight in a Champions League qualifier, however UEFA have confirmed that the game has been postponed due to the overnight clashes.
As reported by CNN, the man was stabbed several times outside AEK's OPAP Arena, and the club's flag has been pictured at half-mast this morning, with fans laying flowers at the location of where the man died.
Eight more fans were injured - with TV channel ERT saying that a child was hit in the head by a rock, while Greek police have confirmed that they have arrested 98 people.
Police said that between 100 and 120 Dinamo Zagreb fans showed up late on Monday near the OPAP arena where AEK fans had also gathered.
The clashes lasted for more than an hour after the visiting team's training session ended and the team left the stadium.
It's said that fans from both sides 'hurled flares, makeshift explosives and stones'.
After the fan's death, Greek authorities had requested that all supporters should be excluded from the match between AEK Athens and Croatia's Dinamo Zagreb at the Opap Arena.
Dinamo Zagreb condemned the incident in a statement which read: 'GNK Dinamo strongly condemns the riots that took place last night in Athens, in which, according to the reports of the Greek police and Greek and Croatian media, rioters from Croatia were involved in an incident with fans of the Greek football club AEK.
'Such events are not in line with the values and ethics we promote as a club and community. We express our deep concern over this incident. Unfortunately, one person lost his life during the riots. GNK Dinamo would like to express its sincere condolences to the family of the deceased.
'Once again, we remind and invite all Dinamo fans not to travel to the match in Greece, considering that UEFA, in agreement with the police, decided that both matches will be played without visiting fans.
'GNK Dinamo remains committed to creating an environment in which love for sport is expressed in a positive way, through togetherness, respect and cooperation.'
Dinamo fans were officially already excluded under a previous ruling by UEFA.
UEFA says what was going to be the second leg in Zagreb next Wednesday will now be the first leg. The second leg will be held in Athens on Friday 18th or Saturday 19th.