The president of Italy's Marche Region has described three powerful new earthquakes on Wednesday as a "catastrophe" and appealed for help.
A number of villages had become isolated, he said, with fallen trees blocking snow ploughs.
European Commission chief Jean-Claude Juncker promised Italy would not be "left alone".
There were no immediate reports of deaths after the new tremors, which were all recorded as above magnitude 5.
Marche was one of the regions worst hit by the earthquake of 24 August, with 46 of its 298 victims losing their lives in a single mountain village there, Pescara del Tronto.
The latest tremors also affected the neighbouring regions of Abruzzo and Lazio and were felt in the capital, Rome.