The pig heads were delivered to a synagogue, the Israeli Embassy and a Jewish exhibition in Rome during the weekend, just before International Holocaust Remembrance Day on Monday, the Italian news agency ANSA reported.
"Let me first of all immediately rid the field of the miserable provocation that just assaulted all of us," Napolitano said. "The perpetrators -- who I hope can be rapidly identified and are only comparable to the same repulsive material used in those packages -- have nothing to do with Rome and the Romans who for human and civil sympathy, democratic awareness, education and culture are close to the men and women of Jewish origins and religion, embracing them in solidarity and in a commitment to a rigorous fight against all forms of anti-Semitism."
The incident has been dubbed a hate crime, ANSA said.
"It's a hideous act, an enormous offense that I do not accept," Italian Holocaust survivor Sami Modiano said. "There are certain things that make me ache, acts that awaken a hate that I didn't think I'd have anymore. I'm a Jew but also Italian. What has happened offends all Italian people."
Italian Foreign Minister Emma Bonino expressed her "firm condemnation of the reprehensible acts of anti-Semitism, which confirm once again the need to multiply our efforts, especially towards younger generations, to keep the memory of the Holocaust alive."