The problem this year has been accentuated because one of the area's main landfills is full meaning that urban refuse collectors have stopped picking up rubbish, which has piled up in the streets.

Emergency workers said on Tuesday 15,000 tonnes of trash had accumulated so far in the city of Naples and its province.

The trash bonfires were started by locals fearing outbreaks of disease if the garbage is left baking in the sun, but health authorities say such fires spread toxic fumes and pose a longer-term risk for inhabitants.

The mayor of Frattamaggiore, a district north of Naples, ordered schools to remain shut on Wednesday, leaving some 10,000 pupils at home for fear their health may be endangered. Council officials said they may close all public offices if the situation worsens.

In another area, San Giorgio a Cremano, frustrated residents put up leaflets saying "We will all die of cholera" and "We are being overrun by rats". The flames of blazing garbage burnt telephone exchanges in one neighbourhood, leaving it cut off.

Italy's President Giorgio Napolitano, who is from Naples, called the situation "tragic" on Tuesday and urged the centre-left government to move quickly to build new dump sites.