Aldo, the melon vendor, sold his fruit on Corso Mille with faked indifference.

Five steps from his curbside stall lay the crumpled body of the 17th victim this month of yet another Mafia war in the Sicilian capital.Two scarlet rivulets trickled into the gutter from the two .38-caliber bullet holes in the head of Guiseppe Marsalone, 59, a minor Mafia boss assassinated by rival clans as part of a drug war.

"I saw nothing," said Aldo, weighing a melon for a customer with a shaky hand. "I heard shots and dived under my stall. That's all."

A police officer shrugged. Above the pavement the shutters had been drawn on the balconies and windows of the tenement houses. Now and then a face peered from a doorway, then withdrew quickly. Ten minutes earlier, before the shots rang out, the Corso, one of Palermo's main venues, bustled with life.

Last December the dead man had been sentenced to 81/2 years in prison on drug trafficking charges. He had been one of the 474 Mafiosi arrested in yet another attempt to control the mob in Palermo.

Of that number, 338 were sentenced last December to a total of 5,000 years in prison. Today only 112 of those sentenced remain in jail. The rest have been released on "legal technicalities."

Marsalone, a stout man known in the underworld as "Il Autista" (the chauffeur) was back in circulation because Palermo could not find a judge willing to preside over the appeals of the sentenced Mafiosi. The last appeal court judge, Antonino Saetta, was killed with his young son in a Mafia ambush two weeks ago.

Last week, defense lawyers for the mobsters went on strike to protest slow court procedure. The key mobster collaborating with police, An-tonino Calderone, refused to talk unless he was given added police protection in his prison cell and transferred to Rome for the next hearing.

Nobody blamed him for his sudden reticence; 10 of the 17 victims in the latest Mafia killings were either Mafiosi who had turned state's evidence or relatives of those who had broken the sacred Mafia law of omerta (silence) by cooperating with investigating magistrates.

The targeting of "canaries" and their families has imperiled plans for a new trial intended to connect the Mafia to government officials, the much-debated tip of the pyramid in the durable symbiosis between the Cosa Nostra and political power in Sicily.

A five-minute walk from the Corso, at the Palace of the Eagles, Palermo's dynamic Mayor Leoluca Orlando, 42, sits in his 17th century Town Hall office protected by armed police in the square outside and bullet-proof windows inside.

The windows were installed after an anonymous sniper armed with an air-rifle recently used the mayor's office for target practice.

The mayor's slogan "No to the Mafia, no to Violence" has caught the imagination of the students who today demonstrate in support of his anti-Mafia measures in a city where until a few years ago no one publicly spoke the word "Mafia" aloud.

Orlando is an anomaly in Palermo, where his predecessor was murdered by the Mafia and another mayor from his Christian Democratic Party next month faces trial for corruption and Mafia links.

Orlando has stitched together a five-party municipal coalition that not only crossed traditional party lines and enjoys the support of the Communist Party, but took from the mobsters and corrupt politicians the right to compete for public contracts, the cornerstone of their power.

The mayor simply had all public contracts transferred to Rome, an innovation that made him the Cosa Nostra's main target and infuriated local business owners.

"But I don't have time to be afraid, I'm far too busy," he said.