The Italian government is to send extra police to two Naples districts where a war between mafia factions has escalated.
Two sections of the Camorra crime gang are competing for control of two neighbourhoods where drugs are sold.
It is estimated the illegal market in the Scampia and Secondigliano areas is worth €100 million ($US126 million) per year.
In recent months, 20 people have been killed during the battle for control over the neighbourhoods.
According to the Il Sole 24 Ore newspaper, cocaine trade in the Case Celesti area alone is worth €300,000 per day.
The BBC reports drugs are freely traded in more than 30 areas across the Scampia and Secondigliano neighbourhoods.
One clan boss, Gaetano Marino, 48, was shot dead in late August on a beach near Rome while on holiday with his family.
The killing came a month after a similar attack in a public square in Nettuno, another coastal town south of Rome, when organised crime suspect Modestino Pellino was shot and killed.