Europol said the suspects were detained in simultaneous police operations in Greece, Austria, Sweden and Britain. Europol, which helped coordinate the raids, said the gang is believed to have earned nearly $10.5 million by smuggling about 100 migrants per day since operations started in 2013.
The suspects included mainly Syrians and Greeks. The alleged ringleader was arrested in the British city of Liverpool. None of their identities have been released.
Europol said the gang is believed to have smuggled migrants, most of them Syrians arriving from Turkey, through Greece and then via the Balkans to other EU member states. The gang did everything from arranging transport to supplying forged travel documents, authorities said.