Citizen Protection Minister Yiannis Economou on Tuesday said that seven senior Greek police officials will immediately be removed from their positions following the serious incidents between Greek and Croatian football hooligans outside the Nea Philadelphia stadium, in which one man was killed.

The fight between fans broke out on Monday evening ahead of the UEFA Champions League third-qualifying-round match between hosts AEK Athens and Croatian club Dinamo Zagreb.

Despite the UEFA’s ban on the away fans, it is still unclear how up to 120 Bad Blue Boys (bbb) fans of Dinamo managed to reach Athens without being stopped by the police, who were informed of the ban.

Minister Economou was quoted by the Greeke ANA news agency as saying that it was “unacceptable” that the Croatian hooligans had been permitted to cross the border and make their way to Athens and that prevention on the part of the authorities had failed.

“He also made it clear that the matter will not stop there, and that there could be more removals and transfers of officers, following an internal inquiry over the handling of the events,” ANA  says.

The internal inquiry will be assigned to a senior officer by the chief of police on Tuesday.

Economou also offered his condolences to the family of the 29-year-old AEK supporter who was stabbed to death and offered assurances of the political will to address and defeat sports violence.

The Greek minister also noted that the problem of fan violence was deep and European-wide, involving supporters from different countries that had created international networks of violence and operated in many countries.

Economou said that he had ordered the removal and suspension of the head of the department for combatting violence in sports venues, as well as the heads of the traffic police of Ioannina, the heads of the three Antirrio-Ioannina highway traffic police departments, and of the Achaia and Corinth national highway traffic police.