Authorities seized two aircraft, a luxury car and equipment used to make fake identity documents, in raids in Belgium and Italy on Tuesday, Europe's policing agency said.

"It is believed that between October and December 2020, at least five smuggling operations took place in five different European countries," Europol said in a statement.

The migrants, mainly Kurds from Iran or Iraq, boarded the private aircraft in Turkey carrying false diplomatic passports.

The flights were usually bound for the Caribbean, but the passengers would never get there, the agency said.

"During stopovers at different European airports including in Austria, France and Germany the migrants left the plane, disposed of their false passports and systematically applied for asylum," the Hague-based agency said.

The crime group charged up to 20,000 euros ($20,000) per person smuggled, and is also suspected of issuing false checks, scamming airlines in an attempt to build its own fleet and defrauding hotels by not paying bills, it added.

The suspects are facing accusations of migrant smuggling, document fraud and money laundering.

The operation was coordinated by Europol and its twin judicial arm Eurojust, together with European police and US law enforcement agencies.