Italian news agency ANSA says authorities have arrested an Italian convert to Islam and a Moroccan resident who met over the Internet and were preparing to fight with Islamic State in Syria.

Sicilian prosecutors who ordered the arrests Wednesday said investigators had identified the Italian suspect, 25-year-old Giuseppe Frittatta, from social media posts. They included extremist propaganda as well as photos of himself holding a knife with a 26-centimeter (10-inch) blade calling for deaths to "all westerners."

The 18-year-old Moroccan, Ossama Gafhir, is alleged to have induced Frittatta toward extremism, and was following stringent fitness routine to prepare for combat.

Frittata — a Sicilian who changed his name to Yusef — allegedly was in contact with extremists in Italy and abroad. The arrests were carried out in northern Italy.