Twenty-five Canadians are among 57 men arrested after authorities shut down an international child-porn network , Toronto police announced Wednesday.

Twenty-five children were rescued, 12 of whom are from Canada, in the year-long investigation into the online trading of child pornography.

Det. Paul Krawczyk, from the child exploitation section of Toronto Police's Sex Crimes Unit, said 57 people including 25 Canadians were arrested on charges of child pornography as part of a massive investigation known as Project Sanctuary.

A total of 218 charges were laid, ranging from making, possessing and distributing child pornography to luring a child under the age of 16 and sexual assault.

Krawczyk said the project was given the code name "Sanctuary" because those responsible for child exploitation feel the Internet is a haven for such behavior.

"We are out there to tell them that they are not safe. We will go out and find them all."

Project Sanctuary was launched in November 2009, when an undercover officer in Toronto's child exploitation unit made contact with a now-convicted 50-year–old man in Conception Bay, Nfld., who was trading sexual abuse images.

Krawczyk said that man was the police's entry point into a massive online network of individuals, all of whom have now been arrested and charged.

"The trading of these images and videos will never go away. However, we believe that the suspects involved in this case have been arrested," Krawczyk told reporters on Wednesday.

Krawczyk would not discuss the undercover operation beyond saying the suspects were connected by the way they shared the images online. He said there was "hundred of thousands, if not millions, of images."

Police said some the images showed children in their infancy.

"There was a lot of very young child pornography," Det. Const. Janelle Blackadar of the Toronto Police Sex Crimes Unit told CTV Toronto. "By young, I mean, infant, toddler abuse. We've seen images of children with an umbilical cord."

Over the past year, 26 U.S. men have been arrested on 56 charges, 25 Canadian men have been arrested and face 131 charges and six European men have been arrested and face 13 charges.

The Canadian men who have been charged range from 20 to 68 years of age. They face a total of 131 charges after the execution of 31 search warrants across the country.

Seven of the Canadians are from the Toronto area. Other Canadians who were arrested were from British Columbia, Alberta, Saskatchewan, Quebec and Newfoundland.

One of the charged is York University researcher and author Richard Dyde, who was released on $10,000 bail.

Krawczyk said some of the names of those arrested have not been released in order to protect the identities of the victims.

Officers said both boys and girls were exploited, some as young as four years old. None of the rescued children were from Toronto, Krawczyk said.

Some of those people arrested in the sweep have already been convicted to sentences ranging from 30 months to 25 years.

The year-long investigation included Toronto police as well as the United States Department of Homeland Security, Immigration and Customs Enforcement, Homeland Security Investigations, 13 Canadian police services and several international police services.