A suspected act of sabotage damaged a small section of a railway route to the Olympic mountain venues of Bormio and Livigno in the early hours of Wednesday, Italian police said, following similar attacks near Bologna over the weekend.
The incident did not cause any disruption to services as technicians worked through the night to ensure safe operating conditions before the busy morning period, a spokesperson at the state-owned railway Ferrovie dello Stato said.
She said no one had claimed responsibility so far.
On Saturday, the first full day of the Milano Cortina Olympic Games, rail infrastructure was damaged near Bologna, causing delays of up to 2-1/2 hours on high-speed, Intercity and regional services.
An anarchist group claimed responsibility for that attack.
The fire overnight near Abbadia Lariana, on the eastern shore of Lake Como, burnt seven cables in a trackside switching unit on the Lecco–Tirano line.