Police said the suspects were arrested a major operation in cities across Italy which targeted the Informal Anarchist Federation (FAI) and another leftist group called the International Revolutionary Front (FRI).
The suspects, all alleged member of the FAI, face charges of terrorist association, forming the FAI and FRI and taking part in subversive activities and using the Internet to plan and instigate these crimes, according to police.
The suspects are accused of plotting and organising attacks against Milan's private Bocconi University in December, 2009, on a government identification and expulsion centre for immigrants in the northeastern city of Gradisca d'Isonzo, and letter bombs sent last year to Italian tax-collection agency Equitalia.
Other attacks attributed to the suspects include ones on Deutsche Bank's offices in the German city of Frankfurt and the Greek embassy in Paris.
Wednesday's 'Ardire' operation included raids on over 40 locations linked to a total of 24 suspects, according to police. It followed an investigation that used phone intercepts, bugs, website and email monitoring and watching suspects.
Two of the suspects arrested Wednesday are currently in jail outside Italy. They are a 44-year-old Spaniard who is in prison in Germany, and 60-year-old Swiss citizen, who is behind bars in Switzerland, police said.
'Ardire' was "an extremely opportune response by the Italian state to anarcho-insurrectionist aggression," Giampaolo Ganzer of the Italian paramilitary police's anti-terrorism unit told journalists in the Umbrian city of Perugia Wednesday.
During operation, police recovered a cache of explosives from a young women's home in Perugia, Ganzer said.
There were "strong international links" between the FAI and Greek anarchist groups, he stated.
None of the 10 suspects arrested Wednesday is accused of involvement in the kneecaping in May of Italian state-owned nuclear company Ansaldo boss Roberto Adinolfi in Genoa, Ganzer stated.
But the attack on Adinolfi was ordered by the same "ideological, theoretical and organisationaal component," Ganzer said.
FAI has claimed the attack on Adinolfi, describing him as "a warlock of the atom" and threatened future attacks against other Italian state-controlled companies.
Italy's police chief Antonio Manganelli on 6 June reiterated earlier warnings concerning the security threat posed by FAI anarchists in Italy and elsewhere in Europe.
"The only structure that carries out terrorist acts is the anarcho-insurrectionist element of the FAI," he said.
Greek anarchist cells were trying create a European network with Italian operatives, he added.