ATHENS (Reuters) -The trial of Greece's Olympiacos football club chairman Evangelos Marinakis and dozens of soccer fans began in Greece on Wednesday, the biggest case of its kind linked to sports-related violence that authorities have vowed to crack down on.

In total, 142 fans face charges of participating in a criminal organisation and causing life-threatening explosions at sporting events.Seven of them are accused of leading the group. They have all denied wrongdoing.