Greek police have arrested 63 people on charges of being members of a criminal ogranisation with links to sports violence, officials said on Tuesday.

Sport in Greece has been marred by violent incidents on and off the pitch in recent years and authorities repeatedly promised to eliminate hooliganism.

Most of the people arrested are fans of Olympiakos sports team. Lawyer Vaso Pantazi, representing two of those arrested, told Reuters her clients have denied the accusations.

The arrests on Monday were part of a wide operation that involved raids at 87 homes and the confiscation of evidence including mobile phones, laptops, knives and airguns.

Police have identified 160 suspected members of the criminal group which has been operating at least since 2019, officials said. They are accused of crimes ranging from illegal possession of drugs, weapons and explosives to robbery and manslaughter.

The investigation was prompted by the death in December of 31-year-old riot police officer Georgios Lyngeridis, who was severely injured by a flare in clashes between riot police and a group of volleyball fans during a match between Olympiakos and Panathinaikos. He later died from his injuries.

More than 400 people had been detained over that incident and most have provided DNA samples. One man is in prison pending trial over Lyngeridis’ killing.

Based on that evidence and testimonies of three witnesses under protection, police built the case which pointed to the existence of a criminal organisation operating in Athens and other Greek cities.

Olympiakos Vice President and legal adviser Alexis Kougias told Reuters that the team and its owner “are not linked to the case and those accused in any way”.

Following the killing of Lyngeridis, the government was forced to take measures including the installation of surveillance cameras at pitches and courts.

To attend matches, fans will eventually need to identify themselves via a government mobile phone application at the entrance of the venue. The system is partly in place.

In August 2023, AEK Athens fan Michalis Katsouris was stabbed to death in violent clashes before a Champions League match between AEK and Dinamo Zagreb. A year earlier, Greece was shocked when 19-year-old soccer fan Alkis Kampanos died in fighting between rival groups.