The eight suspects are foreign nationals in Italy who used fake contracts and documents provided by a complicit textile company to obtain work visas for mainly northern African and Pakistani migrants, the police said in a statement. They have been charged with abetting illegal migration and counterfeiting legal documents.

Police investigator Giuseppe Governale told a press conference on Friday that the head of the criminal gang was a 41-year-old Tunisian man Kamel Khemiri, who was already being monitored by the authorities.

Khemiri had been previously arrested on drug smuggling charges and had demonstrated an intention to carry out attacks in Italy. He is under investigation on terrorism charges.

Governale said that the suspect had pledged allegiance to the so-called "Islamic State" (IS) militant group in a Facebook post. "I am a member of ISIS until I am dead, and if I die, I call on you to join," wrote the Tunisian man. He also posted a photograph of a French flag being trampled with his statement.

The authorities said Khemiri had celebrated the recent terror attacks in Europe, including the one perpetrated by IS in Nice that killed 85 people last month.

Link between terrorism and migrants

"This investigation demonstrates that there is a risk that people close to jihadists can also control people smuggling operations," Franco Roberti, Italy's top anti-terrorism prosecutor, told a local news agency.

The Italian government has often played down any link between terrorism and migration but on Wednesday Justice Minister Andrea Orlando told parliament that IS could be involved in migrant smuggling.

shs/kl (AP, Reuters, dpa)