Security has been boosted in the area of Rome's Great Synagogue and the city's Jewish ghetto in general, sources said on Thursday after the murder of two Israeli embassy staffers outside a Jewish museum in Washington.

Italy's security agencies are focused on averting the risk of copy-cat attacks, the sources said.

Interior Minister Matteo Piantedosi stressed Thursdsay that "I do not think it is the necessary to raise alarms.

"Attention was already at the highest level and we have raised it further," he continued.

"There are thousands of sites that are already under surveillance".