Portuguese police have arrested 47 people on suspicion of distributing child pornography on the internet.
The investigation, which began more than a year ago, led to simultaneous raids at houses and businesses across the country.
Police said 200 officers took part in the operation, the biggest against internet child pornography to have taken place in the country.
Officers seized 58 computers, discs and other computer material, police said.
"Our investigations led to the identification of a group of individuals who exchanged large quantities of pictures and films using peer-to-peer file-sharing networks on the internet," police said.
The suspects, aged between 16 and 60, could face up to three years in jail if convicted.