It is said to be the biggest such deployment in Italy since World War II
Thousands of troops will be deployed in Italian cities from next Monday to help police fight crime, the Italian government has announced.
About 2,000 troops will guard "sensitive" sites such as train stations and embassies. Another 1,000 will go on street patrols with police.
The six-month deployment includes Rome, Naples, Milan and Turin. Some troops will guard migrant holding centres.
Italy's centre-left opposition dismissed the move as "image-building".
Defence Minister Ignazio La Russa said that after six months the government would "make an evaluation to see whether it has worked and should be extended to other cities".
''This is not a militarisation of cities but a clear response to the perceived demand for greater security," he said on Tuesday.
Right-wing leader Silvio Berlusconi swept to power in April's election on a tough law-and-order platform, promising new measures to curb illegal immigration and combat crime.
Interior Minister Roberto Maroni said troops would patrol in uniform, carrying only small arms. But those guarding sensitive sites would have body armour and machine guns, he said.
The soldiers will come from the army, air force, navy and Carabinieri paramilitary police.
The last such deployment was in Sicily in 1992-1998, during an anti-Mafia crackdown. It followed the assassinations of magistrates Giovanni Falcone and Paolo Borsellino.
Reacting to the government's announcement on Tuesday, shadow interior minister Marco Minniti said "it's an image-building operation that risks backfiring".
"Soldiers patrolling the centres of cities that are our greatest tourist attractions is not a very nice calling card for Italy at the height of the tourist season," he said.