Two small bombs exploded Tuesday night, causing minor damage but no injuries at the headquarters of the Northern League party in Varese, local media reported.
The explosive devices, most likely compressed gunpowder, damaged the headquarters' front door, shattered the window glass, and destroyed part of the interior, Xinhua reported.
The home of the leader of the party, Umberto Bossi, is only about 50 meters away from the site. Similar attacks occurred in 2007 and 2009.
The Northern League is the second largest party in Prime Minister Silvio Berlusconi's coalition.