Police briefly evacuated Italy's main railway station on Monday after reports of a man with a gun in the building in central Rome.

There were no reports of any shots being fired and state broadcaster RAI later said a man had been stopped with a toy gun at a different train station in the city.

Normal service at the main station was halted for 27 minutes and the platforms were evacuated, railway operator Ferrovie dello Stato said on its news website and Twitter feed. Police did not say whether anyone had been arrested there.

Rome is on high security alert because of a 48-hour visit to the city by Iranian President Hassan Rouhani. The Iranian delegation was attending an event far from the station at the time of the alert.

Along with many other European countries, Rome raised its security alert last year after gun and bomb attacks killed 130 in Paris. No specific threat to Italy has been officially reported.