The Italian policeman who fired the shot that killed a football fan on Sunday has said his gun went off as he ran to stop rival supporters fighting.
Football violence spread to cities throughout Italy after the shooting
The unnamed policeman, who is under investigation for manslaughter, told a newspaper he had not aimed at anyone.
The death sparked one of Italy's worst days of football-related violence.
Italy's sports minister said officials should consider suspending all play for several weeks, as authorities met to decide their response.
"I have asked the football authorities if there is the possibility of a strong gesture, in particular the suspension of the championships for the next few weeks," Giovanna Melandri said.
Last season Italy's football programme was badly disrupted after a policeman was killed in a riot in Sicily.
'May you be cursed forever'
Sunday's violence erupted after the shooting of Gabriele Sandri, 26, at a motorway service station near the Tuscan city of Arezzo.
Around 40 police were injured in the nationwide disorder.
The Lazio fan, from Rome, was hit by a bullet in the neck as he sat in a car while police tried to stop fighting between followers of his team and Juventus supporters.
Prosecutors have opened an inquiry into manslaughter, though Arezzo police chief Vincenzo Giacobbe said more serious charges could still be laid.
Floral tributes and football scarves were laid outside the shop owned by the family of the dead disc jockey in the Italian capital on Monday.
A note posted on the window of the premises read: "Yesterday a disgusting b*****d killed my son. May you be cursed forever."
But the policeman who fired the shot told the newspaper Corriere della Sera it was a tragic mistake.
The officer, who has been in the force for 12 years, said he fired his pistol more than 200m (660ft) away from Mr Sandri.
The fan was sitting in a car on his way to see Lazio play Inter Milan.
"I was not aiming anywhere, I was not pointing at anyone," the policeman was quoted by the newspaper as saying.
"The first shot I fired in the air and the second went off as I was running. What a fool. Now I know what happened, I am devastated.
"Now I have destroyed two families, that of this boy and mine," he added.
Gabriele Sandri earned his living as a disc jockey
An autopsy was being carried out on Mr Sandri's body on Monday.
Italian PM Romano Prodi has called for a full investigation into the shooting, and described the resulting disorder as "very worrying".
The president of the Italian Football Federation (FIGC) said he was preparing to announce major changes.
"It is a day in which there will be major institutional steps taken," Giancarlo Abete told RAI radio on Monday.
The worst of the disorder was in Rome - home of Lazio - where hundreds of armed fans blocked off one end of a bridge over the River Tiber and torched vehicles.
Sunday's late match between AS Roma and Cagliari was postponed but supporters wielding rocks and clubs turned up anyway outside the Stadio Olimpico.
The mob also attacked a police barracks and the city headquarters of the Italian Olympic Committee, the body which oversees all sport in Italy.
ITALY'S ANTI-HOOLIGANISM LAW
Matches behind closed doors if stadiums do not meet safety regulations
No bulk ticket sales
Preventative bans can be issued to suspected hooligans
Quick trials and harsh sentences for firework and weapon offences inside stadiums
More severe punishments imposed for resisting arrest
Warrants issued from photo or video evidence in 48 hours
Increased search powers
Self-regulation committee set up for sports media
Across Italy seven of the Serie A games started 10 minutes late. Players wore black armbands but atmospheres remained tense.
In other developments:
- Fans in Milan hurled rocks at a police station and beat up two journalists
- In Bergamo, a match between Atalanta and AC Milan was abandoned 10 minutes after kick-off during an attempted pitch invasion
- Supporters in Siena shouted "murderers" at police
- There was also violence at lower league games in southern Italy.
The disorder comes after the Italian government introduced a law in April designed to stamp out football hooliganism following the death of a policeman in rioting at a match in Sicily in February.
Italy's league programme was suspended, and some matches were then played behind closed doors.