Italian prosecutors say that a Tunisian arrested in a sting on an illegal immigration ring had recently gone through a process of self-radicalization, pledging his allegiance to the Islamic State group and celebrating recent terror attacks.

Police told a press conference Friday that the suspect, who was living near Naples, had declared an intention to carry out attacks in Italy but had not yet made any concrete plans.

Authorities said the suspect had celebrated the truck attack in Nice last month that killed 85.

The Tunisian is among eight people arrested following a year-long investigation into a ring that procured false documents to help illegal immigrants, mainly northern Africans and Pakistanis, to obtain residency in Italy.