Rome (CNN) -- Authorities from Italy to the United States arrested 10 people Thursday for allegedly capturing, viewing and disseminating images through an expansive international online pedophile network.
In addition to those 10 taken into custody in Italy, the United States, France and Portugal, 112 have been reported to law enforcement in those and other countries for "association with crime organizations (that were) producing and distributing pedophile material," the prosecutor's office in Florence, Italy, said in a news release.
Domenico Di Somma, an officer in Italy's national police force, the Carabinieri, said the 112 people were part of a larger social network community that included more than 700 people.
A call to a child abuse help line sparked the investigation more than a year ago, said Di Somma, with the prosecutor's office crediting the anti-pedophile advocacy group Telefono Arcobaleno with providing a series of detailed reports.
Since then, the probe -- dubbed Operation Nanny, according to the Italians, while Portugal's national police called it Operation Hot Line 1 -- has involved police in 28 countries, as well as international law enforcement groups such as Europol and Interpol. The Florence prosecutor singled out actions by authorities in San Diego that helped spur the "first raids in the United States" as well as data acquired by American authorities.
The network featured videos and photos of children under 11 years old being sexually abuse and exploited. In one particularly graphic example, a man in one video is depicted abusing a baby who was only a few months old, said Di Somma, who heads a special internet investigation unit out of Siracusa in Sicily.
It was all part of "an extended pedophile community that used the Internet, especially social networks, in order to sexually exploit children and to spread and exchange pedophile material produced at an artisan level," according to the prosecutor's office.
Di Somma said he could not name the social network in which the images were shared because the investigation is still ongoing. He did say that there were four different online communities, all spun from the same pedophile organization.
The operation is believed to have been spearheaded by a 52-year-old man from Milan who was arrested Thursday, said the Italian police officer.
Earlier in the investigation, authorities took into custody a photographer near Venice and his friend near Florence, said Di Somma.
Portugual's Policia Judiciaria announced Thursday that authorities in that country had searched seven houses and taken computers that had "thousands of images and videos of children performing pornographic and sexual acts."
That led to the arrests of four men, between ages 21 and 78, as part of the broader international sting, the Portuguese national police agency said in a news release.
The Florence prosecutor's office said many of those in Europe under investigation have "records" of pedophilia-related crimes.
CNN's Hada Messia and Livia Borghese contributed to this report.