Four migrant-smuggling cells have been smashed in Europe after police launched dozens of raids on the continent.
The gangs charged up to $10,000 per person, transporting them across the Mediterranean on yachts.
More than 1,000 people are estimated to have been smuggled from Turkey to western Europe.
Eleven people were arrested in Italy, including smugglers who navigated the vessels, some of which had been stolen, and Iraqi and Syrian citizens who worked out the logistics.
Police have carried out dozens of raids across Europe and arrested the people charge of four separate migrant-smuggling cells.
Another 18 were arrested in Albania and one was held in Greece.
“Of the arrested persons, four are allegedly the main perpetrators, leading separate cells or groups of the network,” EU crime agency Eurojust said.
“One of them was mainly responsible for the return of the smugglers to Turkey, where they could prepare for new transfers. The gains of the irregular migration transfers are estimated to be at least several hundreds of millions of euros.”
The co-ordinated action is believed to have dealt a serious blow to the lucrative Turkey-Europe sailboat crossings, for which people pay between $6,000 and $10,000 to reach southern Italy, with an eye on northern European destinations.
“We hope to have curbed the phenomenon, for the next few weeks or the next few months,” said Lt Col Giuseppe Giulio Leo, head of Italy’s financial police in the southern city of Lecce.
”Still, we need to take into account that there will be someone ready to join the organisation and take over the various roles.”
The smugglers used sailboats and yachts, but also fishing boats and less seaworthy craft, packing between 30 and 180 people on board, he said.
“Their destination is typically the southern region of Puglia, the closest point, but they often wind up in Calabria due to weather,” he said.
Those arrested are thought to belong to a ring of up to 80 members and to have organised at least 30 smuggling operations.
Those missions transported more than 1,100 people by boat from Turkey to the coast of Puglia, then on from Italy to other European countries, EU law enforcement agency Europol said.
Iraqi brothers Alaa Qasim Rahima, 38, and Omar Qasim Rahima, 30, are accused of running logistics to help the migrants reach northern Europe. They were arrested near Venice.
It is alleged they ran a cell that helped to transport Syrians from Turkey to EU member states using an international network of associates.
Another person, also Iraqi, is accused of helping the smugglers to evade detection in Italy and to return to Turkey through Greece.
“The criminal networks primarily used sea routes for the transfer of migrants from Turkey, via the Eastern Mediterranean road, to their final EU destinations,” Europol said.
“The sea transfers were performed with the use of leisure vessels, mainly yachts, acquired or rented by the criminal network and skippered by novice seamen purposely recruited by the network.”
Payments were made through informal money transfer systems such as hawala, which is used by criminal gangs to move cash without using wires.
Police in Greece are investigating two agencies accused of handling payments.