Three Algerians have been arrested in Italy on suspicion of planning a terrorist attack.
Italy tightened security following the London bombings
The men were detained in Naples and Brescia, and were "potentially operative", police said.
They had contacts with Algeria's Salafist movement, which is believed to have links to al-Qaeda, police added.
Italy has moved before against suspected Islamic extremists, arresting an imam and five other men in June who were suspected of Salafist connections.
The men were named as Yamine Bouhrama, Khaled Serai and Mohamed Larbi, reports Italian news agency Ansa, quoting Naples police.
The Salafist Group for Preaching and Combat (GSPC) is the main armed Islamic organisation in Algeria.
It reportedly wants to topple the Algerian government, create an Islamic state and attack Western interests in the region.
Italy, which has a 3,000-strong military contingent in Iraq, has stepped up security following the 7 July London bombings.
It has conducted several emergency drills in major cities to test its response to a terrorist attack.