At around 4 am on the morning of April 11th in front of the Unicredit headquarter a rudimentary bomb made with four gas canisters, of camping ones, wrapped in a fabric soaked in flammable liquid, with a fuse to which the fire has been attached exploded. The explosion broke and damaged part of the stained glass window and blackened much of the wall.

https://corrieredibologna.corriere.it/bologna/cronaca/18_aprile_11/08-bologna-aprecorrierebologna-web-bologna-2c0f688c-3d53-11e8-8a98-269d6cadfbfa.shtml