Italian Defense Minister Antonio Martino has said threats against Italy by the Islamic militant group that has claimed responsibility for the London suicide bombs attacks are credible.
The Abu Hafs Al Masri Brigade, an al Qaeda-linked group, in an Internet statement posted on Friday morning said they were ready to strike the Italian capital Rome, local media reported.
The group's claims of responsibility for previous attacks have been discredited by security experts.
But Mr Martino told reporters on Friday evening: "According to Italian intelligence it is credible."
"We must get used to it ... Life is always characterised by the presence of risks. We must not give the terrorists what they want, we must not let ourselves be terrorised," he added.
Italy and France announced on Friday they were boosting security to stave off terrorist attacks, as European governments watched the London bombing campaign with growing alarm.
Italian Interior Minister Giuseppe Pisanu on Friday said it might only be a matter of time before Italy was hit.
His increased security measures included greater policing on transport networks and a new law to make it illegal to train people how to use explosives. Italian police will also be given 24 hours to identify detainees rather than the previous 12.
Italy is a close ally of the United States and has 3,000 troops in Iraq. Militants have threatened to attack unless the forces are withdrawn, a move that the government has rejected.
The Abu Hafs al Masri Brigade claimed responsibility for the July 7 train and bus bombs in London that killed 52 people and injured 700. It has also threatened to target Denmark and the Netherlands, as well as Italy.