The massive operation launched this week 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 USD 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.
The migrants were often smuggled in inhuman and dangerous conditions, such as in very small hidden compartments in the floor of buses or trucks, in freight trains or on boats.
In some cases falsified travel documents were used by the migrants. Marriages of convenience were also used as a modus operandi to regularise their status in the EU, Europol said in a statement.
Human trafficking is a global multi-billion dollar business, only ranking behind illegal drugs and arms trafficking, according to the UN Office on Drugs and Crime.
It is believed to generate profits of an estimated USD 32 billion, according to a 2005 report from the International Labour Organisation.
