A football fan was accidentally shot dead by a policeman as he tried to break up a brawl between rival supporters, according to authorities in Italy.

Police say the 26-year-old victim was killed inside a car when an officer opened fire to stop clashes between Lazio and Juventus fans.

The incident, in a country battling a serious soccer hooligan problem, happened outside a motorway restaurant near the Tuscan city of Arezzo.

The shooting of the Lazio fan - described by local officials as a "tragic error" - has triggered anger.

Fans clashed with police in the northern city of Bergamo and when some supporters tried to smash down a glass barrier in the stadium, Atalanta's Serie A game with AC Milan was abandoned.

Inter Milan's match against Lazio had already been postponed in the wake of the tragedy.

At the San Siro stadium, feelings were running high, with supporters shouting anti-police slogans.