Two people have been arrested in northern Italy for allegedly sending thousands of threatening letters - often including toilet paper stained with faeces - to public figures.
Italy's terror threat level is lower than in other European countries but radicalization is on the rise and more must be done on prevention, a government-appointed panel reported on Thursday.
Hidden Isis cells with the power to launch devastating attacks like those seen in Belgium and France are present in Italy, according to a US top intelligence official.
Interior Minister Angelino Alfano has told the Italian public to "stay calm" after a spate of false alarms concerning terrorism attacks in the country over the weekend.
Italy has increased security at its historic monuments in the Vatican, Rome and Milan after a warning from the FBI of possible jihadist attacks, media reports said on Wednesday.
Airspace over Rome will be closed-off to drones during the upcoming Catholic Holy Year, or Jubilee, over fears that the remote-controlled aircraft could be used by the Isis militant group in a terror attack.
The arrest in Italy of a terror suspect posing as a boat migrant has fuelled nightmare scenarios of jihadist infiltration of Europe, but experts say the threat is overblown and attacks by homegrown extremists are more likely.
Security at the Vatican and across Italy has been stepped up because of a perceived heightened risk of attacks by Islamist militants, officials said on Wednesday.
The extreme-right Forza Nuova party on Thursday threatened to release a blacklist of hoteliers hosting migrants, which the group described as a threat to “health and security”.
The US military has moved a team of marines from Spain to southern Italy as a precautionary step in case the US
embassy in Libya comes under threat, officials said Wednesday.
