A police car was set on fire as Lazio fans clashed with local authorities near the Stadio Olimpico before the Italian Cup final on Wednesday.
Italian national news agency Ansa reported that the two policemen who were in the car at the time have been taken to hospital for smoke inhalation, while one also had an injury to his ear.Lazio fans also threw bottles, stones and other objects. Police responded with water cannons and tear gas.
Two other police cars were also damaged while five fans were arrested.
Police said two of them were arrested earlier in the day after a preliminary blockade uncovered a number of dangerous objects in their car, including flares, fireworks and a concealable portable blade.
Lazio went on to beat Atalanta 2-0 to win the Italian Cup for the seventh time in its history.