A train derailment near Italy's financial capital Milan killed between three and five people on Thursday, a fire brigade official at the city's control room said.

State train firm Ferrovie dello Stato said in a statement a regional train, operated by Trenord, derailed at the Pioltello Limito station, some 40 kilometres from Milan, without giving details on potential casualties.

"There are between three and five dead in the accident from what we know at the moment," the fire official told Reuters.

TV channels RaiNews24 and SkyTG24 reported at least two people had been killed and 10 seriously injured, citing emergency services.

Television footage showed fire brigades trying to free people trapped inside the wagons of the train, which were bent by the impact.

Train circulation between Milan and the nearby city of Brescia was halted after the accident, Ferrovie dello Stato said in the statement.

Trenord is a joint venture between railway operator FNM and one unit of state railway operator Gruppo Ferrovie dello Stato.

In a statement FNM confirmed the accident had happened at Pioltello and said its Chairman Andrea Gibelli was on his way to the site. FNM did not give any detail on casualties.