PALERMO, Italy (Reuters) - Italian police seized eight men on Wednesday behind a speedboat smuggling ring that ran people, including possible jihadists, to Sicily from Tunisia, investigators said.

Operations were headed by a Tunisian man who used his Facebook account to spread Islamic State (IS) propaganda, they said. He remains at large and is wanted for inciting terrorism.

The paramilitary Carabinieri’s early morning sweep netted two Italians, with the rest mainly Tunisian.

As well as the IS promoter, six others, again mainly Tunisian, are sought for arrest on suspicion of people smuggling and trafficking in illegal cigarettes.

The group was “a real and concrete threat to national security because it was able to offer many irregular migrants a secret sea passage that was safe and fast,” the arrest warrant said.

The route to Sicily “was particularly attractive to subjects sought by Tunisian law enforcement for past crimes or because suspected to be connected to religiously motivated terrorist groups,” it added.

The investigation began in 2016 after a Tunisian man held in an Italian prison offered information saying he wanted to protect Italy from “an army of kamikazes”, the warrant said.

Using speed boats, the smugglers reached the southwest coast of Sicily within three-and-a-half hours carrying a handful of migrants and often other contraband, like cigarettes or hashish, according to testimony from the turncoat.

Police documented five smuggling trips, but many others are suspected to have taken place, one investigator said, because they were discussed in intercepted telephone conversations.

Italy’s Interior Minister Matteo Salvini lauded the operation on Twitter: “People smugglers and terrorists - stay home!!!”