A man aged 20 has been arrested in northern Italy on suspicion of plotting an attack on a synagogue in Milan.

Israeli facilities in North America -- and around the world -- are on high alert, according to an internal security document obtained by ABC News that predicted the threat from Iran against Jewish targets will increase. "We predict that the threat on our sites around the world will increase … on both our guarded sites and 'soft' sites," stated a letter circulated by the head of security for the Consul General for the Mid Atlantic States, Eliran Avitan. Guarded sites refers to government facilities like embassies and consulates, while 'soft sites' means Jewish synagogues, and schools, as well as community centers like the one hit by a terrorist bombing in Buenos Aires in 1994 that killed 85 people.