More than 100 were arrested in what authorities called one of the largest efforts ever to break an Internet child pornography ring.
The British National Crime Squad coordinated the pre-dawn raids as part of a five-month investigation into the Wonderland Club, which authorities said exchanged pornographic pictures of children as young as 2 years old on the Internet.
During the investigation, police found a database containing more than 100,000 pornographic photographs of naked boys and girls and confiscated computers and computer programs from dozens of suspects.
Police targeted 180 suspects and arrested more than 100. The raids took place on three continents in Australia, Austria, Belgium, Britain, Finland, France, Germany, Italy, Norway, Portugal, Sweden, and the United States.
"I am unaware of another police operation that has ever pulled together so many law enforcement agencies worldwide to effect simultaneous raids and arrests," said Bob Packham, deputy director general of the National Crime Squad.
Police said 23 addresses were raided in the United States, where the pornographic ring originated. The investigation began earlier this year when Sussex police in southeast England discovered pedophiles downloading child pornography from the Internet, authorities said.
The federal crime office in Wiesbaden, Germany, said investigators arrested three suspects in Stuttgart in southern Germany, near Kassel in central Germany and in the eastern town of Freiberg.
Police said up to 10 other countries were planning additional raids in connection with the ring.
"The content would turn the stomach of any right-minded person. It's really disgusting," said Detective Superintendent John Stewardson, who led the operation.
Police said they would now attempt to trace some of the children in the pictures in an attempt to offer them support and counseling.