(CNN) -- Officials are calling it one of the largest operations against human traffickers in Europe.
Police in Europe arrested 103 people in 10 countries this week, all accused of smuggling in people on boats, freight trains and small hidden compartments in the floors of buses and trucks.
The massive operation spanned a host of European nations and deployed more than 1,200 police officers.
The operation descended on homes and properties across Croatia, Czech Republic, France, Germany, Greece, Hungary, Poland, Slovak Republic, Turkey and Kosovo region in the early hours of Tuesday morning. Related operations took place in Switzerland and Austria.
Their search yielded 176,500 euros (about $240,000) in cash, plus a collection of mobile phones, laptops, bank statements and a semiautomatic rifle with a large amount of ammunition.
"All arrested persons are suspected of being involved in the clandestine smuggling of a large number of irregular migrants into and within the European Union mainly via Turkey and the Western Balkan region," a Europol statement said. Europol is the European Union's law enforcement agency,
Most of those being smuggled were recruited from Afghanistan, Iraq, Pakistan, Syria and Turkey by the criminal ring targeted in these raids.
Human trafficking is a global multibillion dollar business, only ranking behind illegal drugs and arms trafficking, according to the U.N. Office on Drugs and Crime. It is believed to generate profits of an estimated $32 billion, according to a 2005 report from the International Labour Organization. Half of those profits come from industrialized nations.