The Italian army has been ordered to clear tonnes of uncollected garbage from the rubbish-strewn streets of Naples a week before local elections in the country's third biggest city.

The government order comes as Berlusconi is due to hold a rally in Naples on Saturday before the first round of voting on Sunday and Monday and drew an outraged reaction from the centre-left opposition.

"It is very bad to see the prime minister remember about Naples's garbage crisis a week before the election," Angelo Bonelli, head of the Greens party, said.

Local authorities said the 175 soldiers deployed to the city will begin cleaning the streets, where more than 4,000 tonnes of garbage lie uncollected, from Tuesday, starting with hospitals and schools. Defence Minister Ignazio La Russa said on Monday he hoped it would be the last time that the army -- which has been sent to Naples on garbage duty several times in the past -- would have to step in.

But despite Berlusconi's repeated pledges to solve the chronic garbage crisis in Naples once and for all, trash is again piling up, with refuse dumps overflowing.

Firefighters were called out 23 times overnight after residents set fire to festering piles of garbage.

With the city's only incinerator not working at full capacity, the soldiers will move the refuse to dumps in other parts of Italy.

Berlusconi, who often cites clearing the streets of Naples shortly after returning to power in 2008 as one of his government's main successes, has blamed local politicians for the problems, but angry protesters say it is the government's fault.

Naples, together with Milan, Bologna and Turin, is one of the main cities up for grabs in the May 15-16 local elections, regarded as an important test for Berlusconi's government as he battles scandals, trials and a stagnating economy.

Reuters