ROME — It was just a few days ago when Italian football officials were hailing the return of Serie A clubs to the final phases of Europe's top club competitions.
Now it's back to the more familiar problems of fan violence.
Before Sunday's Turin derby, Torino fans attacked the bus carrying Juventus' players as it approached the stadium, breaking a window. Juventus supporters retaliated by throwing fireworks at Torino counterparts inside the stadium, injuring several when pieces of seats started splintering in the air.
At least five people were arrested.
"Complements to the police who identified and arrested those responsible for the assault on Juve's pullman and the explosion that occurred inside the stadium," Italian Interior Minister Angelino Alfano said. "There will be no clemency toward the enemies of sport. These are hooligans."
Relatedly, Roma's American president, James Pallotta, has been waging a verbal battle with his club's hardcore "ultra" fans, who have been disorderly all season.
"All Alfano needs to do is what we've been asking him to do for some time, which even an 8-year-old kid would do: Apply the English law and put police inside the stadiums," said Napoli president Aurelio De Laurentiis. "But he turns a deaf ear."
Last week, Juventus advanced to the Champions League semifinals while Fiorentina and Napoli qualified for the Europa League's last four — marking the first time Serie A has three clubs so far in those competitions since 2003.
"I'm tired and frustrated of seeing prestigious results by our athletes placed next to this type of news," said Giovanni Malago, the president of the Italian Olympic Committee, which oversees all sports in Italy. "The damage is incalculable."
Serie A resumes right away with a midweek round.
On Tuesday, it's Udinese vs. Inter Milan. On Wednesday, it's: AC Milan vs. Genoa; Cesena vs. Atalanta; Chievo Verona vs. Cagliari; Juventus vs. Fiorentina; Lazio vs. Parma; Palermo vs. Torino; Sampdoria vs. Hellas Verona; and Sassuolo vs. Roma. On Thursday, it's Empoli vs. Napoli.
Here are a few things to know about this week's matches:
Juventus can clinch its fourth straight title with five matches to spare if it beats Fiorentina and Lazio does not beat Parma.
Juventus would also seal its 31st "scudetto" if it draws against Fiorentina, Lazio loses and Roma does not win at Sassuolo.
Juventus enters with a 14-point lead over Lazio and a 15-point advantage over Roma and holds the tiebreaker edge over both Roman clubs courtesy of better head-to-head records.
After Napoli, struggling AC Milan has also begun a full-time training camp, which could last until the end of the season.
Milan announced Sunday that the training camp — requiring players to sleep at Milanello — is "open ended."
The move comes after Milan's four-match unbeaten run was halted by a 2-1 loss at Udinese on Saturday, leaving the Rossoneri in 10th place.
Filippo Inzaghi's side was completely dominated until Giampaolo Pazzini pulled a goal back in the 88th minute with a leaping header to take advantage of Milan's only on-target attempt of the match.
"The duration of the training camp is open ended," a Milan statement said. "The squad could remain at Milanello until Wednesday, or until May 3, 10, 17, 24 or 31, depending on the decisions of Milan's coach, which will be taken based on the quality of the performances."
Crisis-hit and last-place Parma put off relegation for at least a few more days by beating Palermo 1-0 Sunday.
If not for a seven-point penalty stemming from unpaid wages, Parma would have a legitimate chance of avoiding relegation despite being declared bankrupt.
"We're showing that we still have a lot of desire to do well during this tortuous season," Parma coach Roberto Donadoni said.
Andrew Dampf can be followed at http://www.twitter.com/asdampf