Such expulsion orders, with no option for appeal, are one of the main planks of Italy's strategy for preventing the kind of jihadist attacks suffered by other European countries.
The latest suspects to be kicked out included a 38-year-old Moroccan who was said to have been radicalised while in prison for minor crimes.
Italy arrests asylum seeker for inciting terrorism
His status was bumped from medium to high risk after he and other prisoners were seen enthusiastically celebrating the Stockholm truck attack in April which killed five people.
The Syrian, who also operated under a false Tunisian identity, was arrested in 2015 for involvement in illegal immigration and placed under house arrest at an asylum seeker centre in southern Italy.
There, he was abusive to staff and residents, was seen trying to convert a fellow resident to Islam and also celebrated the deadly attack that killed 22 at a Manchester concert in May.
The suspect, whose age was not released, had managed to avoid the application of two previous expulsion orders issued in 2011.
The third man expelled was a 31-year-old Moroccan whose expressions of support for the Islamic State (IS) group were thought to be linked to a psychiatric disorder for which he received compulsory treatment after being arrested for theft.
The interior ministry said all three had been flown back to their respective countries of origin.
Italian village offering people $2,100 to relocate there
Italy is regularly threatened by IS propagandists and has stepped up security at major tourist sites and places where large groups of people congregate.
But officials say they have yet to be alerted to an imminent terror threat and a government panel said in January that the risk of attack by a homegrown militant was lower than in neighbouring countries.
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