WASHINGTON ( CNN ) -- More than 170 people around the globe , including at least 61 in the United States , have been arrested in a major operation targeting international child pornographers , officials said Friday . Attorney General Michael Mukasey and European Union representatives announced the sting 's results Friday . Operation Joint Hammer has rescued 11 girls in the United States , ages 3 to 13 , who were sexually abused by child pornography producers , U.S. Attorney General Michael Mukasey and representatives of the European Union said at the Justice Department . Dozens more were located in Europe , including several young female victims in Ukraine . Authorities found connections between producers , distributors and customers in nearly 30 countries as a single investigation grew to a global inquiry into the dark corners of brutality and child abuse . The investigation , code-named Operation Koala in Europe , was developed when investigators determined that a pornographic video found in Australia had been produced in Belgium . `` This joint EU-U.S. coordinated effort began with the discovery in Europe of a father who was sexually abusing his young daughters and producing images of that abuse , '' Mukasey said . Further investigation showed a number of online child porn rings . Some included dangerous offenders who not only traded child pornography but also sexually abused children , the officials said . Agents are still attempting to locate child victims whose images have appeared in photos and videos , and more arrests are expected as the FBI , Immigration and Customs Enforcement and the Postal Inspection Service continue the investigation . A Postal Service official said ringleaders primarily targeted prepubescent female victims to satisfy their customers but noted that other groups produce photos and videos of boys and girls of all ages -- or even infants . `` For this subset , that 's what turns them on , '' the official said .
U.S. , European officials search for child pornographer sting . 11 girls ages 9 to 13 found in the United States , dozens more found in Europe . They turn up people who made child porn , sexually abused children , officials say . Inquiry starts with pornographic video found in Australia that came from Belgium .