Italian police issued more than 100 arrest warrants in a crackdown against suspected mafiosi in Naples today, detaining dozens, including three men suspected of one of the region's bloodiest shootings.

Police said several suspected high-ranking members of the Casalesi clan were held in the pre-dawn raids, including Giuseppina Nappa, the wife of Francesco Schiavone -- who investigators believe is running the group from jail.

Authorities took control of buildings and seized business activities worth 100 million euros ($143 million).

Interior Minister Roberto Maroni described the operation against the Casalesi as memorable. The Casalesi is regarded as a main player in the Camorra -- Naples' version of the Sicilian Mafia.

"We have dealt a very big blow to the Casalesi clan," he told a news conference in Rome.

Of the arrest warrants issued, 76 were served on suspects already being held in jail on other charges. At least five are still at large.

Three of the 29 detained are suspected of killing six immigrants from Ghana, Togo and Liberia in Castelvolturno, a town near Naples, earlier this month in one of the most brutal Camorra shootings in recent memory.

Further details of the arrests were not yet available.

Maroni has sent 900 soldiers and extra police to the area to fight what he has called a "civil war" between the Camorra and the state.