Italy has increased security in the country’s tourist attractions after warnings were made last week of a possible attack on Easter Sunday.
Police in Florence searched tourists with handheld metal detectors while higher than usual numbers of uniformed officers patrolled the canals and churches of Venice.
The United States was criticised by Italy after the US embassy in Rome warned Americans could be targeted in terrorist actions in Venice, Florence, Milan or Verona. The warnings were made without consultation with Italy.
Tensions have increased after the assassination of a senior government advisor which was claimed by an offshoot of Italy's Red Brigades guerrilla movement.
The United States did not identify the people suspected of planning attacks at Easter but security sources have said the threat came from Muslim militants looking to avenge the U.S.led war on Afghanistan.