Calling for more police and judicial resources, he added: "Our byword should be 'continuity,' because we must fight 365 days a year against the mafia."
The demonstrators included family members of victims of mafia violence such as Rita Borsellino, who offered a grim prognosis for the future.
"I am angry and less optimistic than 17 years ago, when my brother was slain," said Borsellino, whose brother, a judge, was assassinated in the centre of the Sicilian capital, Palermo.
Together, the four Italian mafia -- Sicily's Cosa Nostra, the Naples-area's Camorra, Calabria's 'Ndrangheta and Puglia's Sacra Corona Unita -- have killed more than 900 people in recent decades.
"The mafia have changed, they have become more dangerous, better inserted into the web of power," Borsellino said, as she too called for more government help.
Investigative journalist Roberto Saviano, whose best-selling book has been adapted into a cinema hit -- and who faces a death threat from the Camorra as a result -- also made a surprise appearance at the protest.
In a separate and bizarre incident, 300 men from rival mafia clans gathered for a church ceremony in Calabria Friday aimed at putting to rest a bloody feud that has killed a dozen people since 1991, the daily Corriere della Serra reported.
The ceremony reportedly broke a tradition in the village of San Luca banning men from entering the local church.
"The village is convinced it is the victim of a curse and that it needs the blessing of Jesus to end it," the newspaper reported.
A local bishop accepted to bless the village, but only if all San Luca's men -- and only its men -- came to the church to pray.
------------------------------------------------------------------