Four VIP guests of Greek club PAOK were injured after their bus was attacked by Croatian football hooligans who threw stones and flares, smashing windows and setting the vehicle alight.
Zagreb police spokeswoman Jelena Bikic said the attack was carried out at a crossroad in Zagreb by a group of about 40 people, 11 of whom were detained and found to already be on a hooligan register. Local media said they were probably fans of Dinamo Zagreb, which plays a crucial Europa League match against PAOK on Wednesday.
The bus was one of three taking PAOK's guests from the airport to their hotel and they were driving under police escort. The attack was carried out in such an organized way that the escort couldn't prevent it, Bikic said.
Seven of those attacked refused medical help, she added.
Dinamo expressed regret about the incident and said it hoped that UEFA wouldn't hold the club responsible as "the attack happened far away from the stadium."
Dinamo has been fined by UEFA several times in the past because of trouble from their fans at matches in Europe.