Fifty children have been rescued and nine people arrested after an Interpol investigation into an international paedophile ring.
The arrests were made in Thailand, Australia and the US and more are expected, Interpol said.
The investigation began in 2017 and focused on a hidden “dark web” site with 63,000 users worldwide.
Police believe 100 more children have suffered abuse and are working to identify them.
Operation Blackwrist was launched by Interpol after it detected images showing 11 boys aged under 13 being abused on a site where people can use encrypted software to maintain secrecy.
The dark net is an internet area beyond the reach of mainstream search engines.
The US Homeland Security Investigations (HSI) department traced the IP address of the website, which was hosting photos and videos of abuse.
Police say the abusers uploaded new images on a weekly basis and often masked the children’s faces to make it harder for investigators to identify them.
The first arrests came last year, when the site’s main administrator, Montri Salangam, was detained in Thailand, and another administrator, Ruecha Tokputza, was caught in Australia.