Italian football has once again been shattered by a fatal tragedy after a Lazio fan was shot dead during scenes of disorder at a motorway service station.
The 26-year-old supporter, a disc jockey named Gabriele Sandri, was shot as police attempted to intervene to quell trouble and a police spokesman all but confirmed media reports that the fatal bullet came from a police weapon.
Elsewhere, the match between Atalanta and AC Milan was abandoned after seven minutes because of crowd disturbances while Roma's evening match with Cagliari was called off after the Eternal City club had asked for it to be put back out of respect to the Lazio fan - Lazio and Roma share the Olympic Stadium in Rome.
The incidents come nine months after policeman Filippo Raciti was killed during crowd trouble surrounding the Sicilian derby match between Catania and Palermo.
That led to draconian security measures adopted by the Italian government with numerous stadia closed until they made improvements to ensure better security.
The Italian government also created an independent body, L'Osservatorio nazionale sulle manifestazione sportive, to clamp down on football violence and gave it powers to call games off or ban fans from attending.
Vincenzo Giacobbe, head of police at Arezzo where the incident took place, confirmed that a man had died and did not deny media reports that the fatal bullet had come from a police weapon.
'This is a tragic mistake,' he said. 'Our agent had intervened to prevent the fracas between two groups of people - that had not been considered fans - degenerating into a situation with serious consequences for both groups.
'I express my most profound pain and sincere condolences to the victim's family.'
As news broke of the shooting, the reverberations were felt elsewhere even though Italian Football chiefs, as well as calling off Lazio's game with Internazionale in Milan, initially ordered that the remaining matches kick off 10 minutes later as a mark of respect to Sandri.
Fighting marred the build-up to the Atalanta-Milan game and then referee Massimiliano Saccani took the teams back to the changing rooms after seven minutes of play when Atalanta fans attempting to invade the pitch.
The official decided after a 25-minute wait to call off the game.
AC Milan defender Alessandro Nesta, a member of Italy's World Cup winning squad, said: 'We all came out ready to play.
'Unfortunately, certain episodes happened with Atalanta fans trying to provoke the suspension of the game.
'But the problem is not inside the stadia. The problem is that what happens inside the stadia is a reflection of our society.'
Italian prime minister Romano Prodi expressed his shock over Sunday's events.
Prodi was in church when a government aid informed him that Sandri had died.
Prodi said: 'These are episodes that increase concern.
'I was made aware of the situation by the minister of interior while I was at mass.'
A Lazio spokesman, Giacomo Mazzocchi, said of the incident: 'It's shocking and inexplicable. We are still asking ourselves how could something like this have happened. It's a tragedy.'
FIGC president Giancarlo Abete initially had ruled that all games bar the Inter-Lazio game should go ahead.
Speaking before the abandonment of the Atalanta-Milan game and ahead of the decision to postpone the evening match between Roma and Cagliari, Abete said: 'I would be intellectually dishonest if I said that we had not considered postponing all of today's games.
'But in the end, we believe that we have taken the right decision.
'The incident has yet to be clarified and it should not create any animosity between the fans and the police because what has happened is not yet clear.'
Roma's later request to call off their game with Cagliari was eventually approved with Lazio's city rivals determined not to rub salt into the wounds of their co-tenants at the Olympic stadium.
The club's managing director Rosella Sensi said: 'It is right to ask for the game to be postponed as a sign of solidarity for the Lazio fans and for the city of Roma hit by the death of Gabriele Sandri.'