ROME: Italian police on Tuesday arrested four people suspected of carrying out an October bomb attack targeting a prominent journalist who had been threatened by the mafia.

The blast in a residential neighborhood of Pomezia, some 20 kilometers (12 miles) south of Rome, destroyed two cars belonging to Sigfrido Ranucci, known for investigations into corruption and the mafia.

He has lived under police protection for several years because of death threats.

The Carabinieri police said the four suspects detained near Naples were “strongly suspected... of the offenses of possessing, carrying and using explosive devices in a public place, of making threats and causing damage, with aggravating circumstances due to having acted in a group of more than five people and using mafia-style methods.”

Three of them have been placed in pre-trial detention and the fourth is under house arrest.