More than 100 people have been arrested in 18 countries across Europe after an investigation into child sex offenders using the internet. Arrests were also made in Canada.
The pan-continental police force, Europol, says Operation Typhoon has now been concluded.
The BBC reports that the suspects had different professional backgrounds, some of them being teachers or caretakers in close contact with children.
Five children aged between four and 12 have been identified as victims of sexual crimes.
Europol says its investigation was led by Austria's Criminal Intelligence Service (.BK), which had detected an internet service provider misused by child sex offender groups to distribute illegal content on the internet.
Log files collected by .BK were then sent to Europol together with offending images.
The 221 suspects - 115 of whom have been arrested - were detained during house searches in Austria, Belgium, Britain, Bulgaria, Canada, Denmark, France, Germany, Hungary, Lithuania, Luxembourg, Malta, the Netherlands, Poland, Romania, Slovakia, Slovenia, Spain and Switzerland.