ROME - Police rounded up suspects yesterday in eight European countries as they cracked down on a human-trafficking organization that had smuggled thousands of Iraqi Kurds into Europe aboard trucks, sometimes stuffing them into cages or hiding them in vending machines, authorities said.

Beginning in 2006, the Kurds traveled from Iraq through Turkey to Greece, where smugglers hid them in trucks that crossed the Adriatic on ferries and docked in Italy, said Venice police official Alessandro Giuliano, who coordinated "Ticket to Ride," the operation that arrested the suspects.

Some of the illegal immigrants were hidden inside empty drink-vending machines and cages loaded on the trucks, police said.

At least three Iraqi Kurds being smuggled into Europe suffocated. Their bodies were found in 2007 in a truck loaded with watermelons on its way to Venice from Greece, Giuliano said.

"They treated these people like merchandise," he said.

The illegal immigrants allegedly paid $4,000 to $8,000 each for their journey.

The smugglers had bases in Iraq and Turkey, police said.

In the coordinated operation, authorities issued 46 arrest warrants. Most suspects were picked up in 16 Italian cities, police said, but 14 were detained abroad, mainly in Germany, but also in France, England, Belgium, Switzerland, Greece, and Sweden.