Train passengers in Italy on Monday suffered four-hour delays and more than two dozen train cancellations after an arson fire in Rovezzano near Florence.
The fire was likely "malicious", the Italian state railway manager RFI said in a statement, citing "initial investigations" into the incident.
RFI said that more than 50 technicians had worked to restore burnt cables in the aftermath of the fire.
The average delay was three hours by the afternoon, the railway manager said.
Police said the fire may have been started by an anarchist group related to the ongoing trial of 28 anarchist members in Florence, according to Italian national news agency ANSA.
A post on the known anarchist website Finimondo.org further fueled suspicion when it wrote in a post that the fire could have been "a gesture of love and anger".
Italy's Minister of the Interior Matteo Salvini reacted to the incident on Twitter, posting photos from the site and stating that the act would not go unpunished.