French and Italian police swooped yesterday on alleged Islamist terrorists in an international operation.
Italian officials in Milan said police were armed with 120 arrest warrants for the round-up, designed to prevent any extremist attacks on the football World Cup finals in France next month.
Nine people were detained in northern Italy.
In Paris and other main cities in the country, hundreds of French police were hunting for people on the list.
French police sources said German and Belgian police were also co-operating.
The French police were operating on the instructions of four examining magistrates specialised in terrorist cases.
Those being hunted were individuals and groups suspected of supporting Algeria's outlawed Armed Islamic Group.
Police hope to question them to uncover international links with the group, which is waging a brutal war to install fundamentalist rule in Algeria.
France is concerned that the World Cup will be disrupted by bombings to draw attention to the Algerian crisis and to punish Paris for its support for Algeria's military-backed Government.
Islamic extremists are believed to have been behind a series of bomb attacks in France in 1995.