Vice-Prosecutor of Areios Pagos, Greece's supreme court, Zacharias Kokkinakis sent a notification to the country's court of first instance prosecutors on Friday, urging for their vigilance in the prevention and drastic tackling of crimes deriving from sports violence. Kokkinakis noted that such crimes must be processed by the judicial system within 30 days, wherever possible. On the same day, a request was sent to police authorities by order of Sports Prosecutor Kostas Spiropoulos for the immediate investigation of such crimes in Athens and elsewhere. Meanwhile on Friday, major operations were carried out in associations run by football fans in both the cities of Athens and Thessaloniki, in search of illegal weapons and other items that could cause grievous bodily harm. These were ordered in the aftermath of the football-motivated crime in Thessaloniki's Harilaou district on Tuesday, where a 19-year-old was stabbed to death and two others were injured solely because of their support for a rival football team. A 23-year-old was charged with murder and attempted murder, committed jointly with others. The same person was also sentenced by a different court on Thursday to 4 years and 3 months in jail without suspension and a 2,200-euro fine over misdemeanors related to possession of arms, among others. A police operation was carried out by the Hellenic Police in Attica on Friday, in the areas of Omonoia, Peristeri, Agioi Anargiroi and Ilion, with dozens of police officers from various departments visiting and inspecting these associations. In the central Athens district of Omonoia, several potential weapons were found and confiscated: a knife, an axe, two flares, 15 wooden poles and one metal pole, eight wooden rods with screws, 14 motorcycle helmets, six spray paints of different colours, 11 smoke-barrels and a video recording system. A similar operation was carried out in the city of Thessaloniki on the day, where two men aged 46 and 36 years old, respectively, were arrested and later released on Friday during a police operation that involved simultaneous raids on 13 associations and groups of football club supporters. The two men were heads of two supporter groups and were immediately led before a Thessaloniki Misdemeanors Court, which postponed the hearing of their case and ordered their release until trial, which will take place in the next few days. Both men are accused with illegal weapons possession and possession of times that can cause bodily harm, all of which were found on the premises of the two associations they run. These included knives, crowbars, metallic and wooden objects and other items. The 43-year-old has additionally been charged with operating a supporters' club without a license. READ MORE: The joke of Giannis Antetokounmpo that “froze” Thanasis – Watch the hilarious video.