An Internet pedophile ring with up to 70,000 members — thought to be the world's largest —has been uncovered by police, a security official said Wednesday.

The European police agency Europol said in a statement that "Operation Rescue" had identified 670 suspects and that 230 abused children in 30 countries had been taken to safety. More children are expected to be found, Europol said.

It said that so far 184 people had been arrested and investigations in some countries were continuing. Most of those detained are suspected of direct involvement in sexually abusing children.

They include teachers, police officers and scout leaders, AP reported. One Spaniard who worked at summer youth camps is suspected of abusing some 100 children over five years.

Europol director Rob Wainwright said Wednesday the ring, which communicated using an Internet forum, was "probably the largest online pedophile network in the world."

Cori Bassett, a public affairs officer for U.S. Immigration and Customs Enforcement, said in an email that there had been five arrests and four convictions in connection with Operation Rescue in the U.S.

"Arrests so far have been made in Georgia and Connecticut. ICE continues to pursue the leads provided by Europol," she added.

The website was shut down following the three-year investigation, Europol said.

"The website operated from a server based in the Netherlands and, at its height, boasted up to 70,000 members worldwide," it added.

"It attempted to operate as a 'discussion–only' forum where people could share their sexual interest in young boys without committing any specific offences, thus operating 'below the radar' of police attention," Europol said.

"Having made contact on the site, some members would move to more private channels, such as email, to exchange and share illegal images and films of children being abused. Computers seized from those arrested have harvested huge quantities of child abuse images and videos," it added.

Police infiltrated site

The Europol statement said U.K. and Australian police infiltrated the site to identify the members who posed the greatest danger to children. Police also sometimes posed as children online as part of the investigation.

Law enforcement authorities from 13 countries, including the United States, Australia, Canada, Italy, Spain and the U.K., were involved in the case, Europol said.

The statement said Europol analysts had cracked the security features of a key computer server at the center of the network which uncovered the identities of suspected child sex offenders.

And, after his arrest, the forum's Dutch administrator helped police break encryption measures that shielded users' identities, allowing police to begin their covert investigations.

"Europol subsequently issued over 4,000 intelligence reports to police authorities in over 30 countries in Europe and elsewhere, which has led to the arrests of suspects and the safeguarding of children," Europol said.

Wainwright said he was proud of the "exceptional work of our experts in helping police authorities around the world to record these groundbreaking results."

"The safeguarding of so many vulnerable children is particularly rewarding and demonstrates the commitment of our agency to make Europe a safer place for its citizens," he added.

The investigation was led by Britain's Child Exploitation and Online Protection Center.

Peter Davies, of the center, said there would be more arrests as the investigations continue.

"Those who have been members of the site can expect a knock on the door in the very near future," he said.

In Britain, police said, the children involved were aged between 7 and 14.

Australian Federal Police commander Grant Edwards said suspects arrested in Australia ranged in age from 19 to 84 and used the Internet to "prey on children with anonymity, with subterfuge and with camouflage."

Children, Edwards said, "should be able to use the Internet safely, without fear of being approached or groomed by these online predators."