ROME — Italian authorities detained four people today accused of taking part in riots triggered by the accidental killing of a soccer fan by a policeman — the latest episode of soccer-related unrest in the country.

Gabriele Sandri, a 26-year-old disc jockey from Rome, died after getting hit in the neck by a bullet while sitting in a car when a policeman fired a warning shot to disperse a clash Sunday.

Police said they intervened to stop a scuffle between two groups at a rest stop — Sandri's Lazio fans and a small group of Juventus fans.

Sandri's death forced the suspension of three Serie A matches as clashes erupted in Rome, Milan and other cities. Enraged by the shooting, rioters smashed windows, hurled stones at police cars and set trash bins and police vans on fire.

In the Italian capital, violent fans rioted into the night, attacking police barracks near the Stadio Olimpico and raiding the nearby Italian Olympic Committee headquarters. By morning, four people were picked up in Rome, police said. About 40 police officers suffered injuries, ANSA said.

TEHRAN, Iran — President Mahmoud Ahmadinejad today labeled his critics at home "traitors," and accused them of spying and collaborating with Iran's enemies, state media reported.Ahmadinejad, who is facing growing domestic criticism over his hardline policies that have led to U.N. Security Council sanctions, did not specifically name any of his critics.But Ahmadinejad said that he has resisted pressures not only from the West but also from critics at home and he vowed to eventually publicly expose them."They sent people to the enemy to regularly give them information from within the ruling system every week," the official IRNA news agency quoted Ahmadinejad as telling a group of students at Science and Industry University in Tehran.Ahmadinejad's critics have stepped up vocal warnings in recent months that the president's hardline policies and defiance against international demands to roll back Iran's nuclear program were turning more countries against Tehran.By The Associated Press