Italian authorities launched a major sweep in the north around Milan, where more than 170 policemen searched 40 houses at dawn, a police statement said.
Italian police have been accused of
casting a dragnet for Muslims
The raid was “part of a massive operation against international terrorism coordinated with the Milan prosecutor, Luigi Orsi”, said the statement.
The financial police said they were investigating numerous companies, suspected of helping fund Islamists.
The statement said police were hunting seven suspects.
Six of the seven were detained while one remained at large or might have been already arrested in Tunisia.
Those arrested included five Tunisians and a Moroccan, police said.
The suspects are accused of giving logistical help to a cell of the Algerian Salafist Group for Preaching and Combat (GSPC).
GSPC is a suspected armed Islamist opposition group active in Algeria and targets Algerian security forces.
The detainees are also accused of criminal association, aimed at assisting and financing a “terrorist” organisation, false accounting, involvement in illegal immigration, receiving counterfeit documents and trafficking in stolen cars.
Italian authorities had initially claimed that the GSPC cell in Milan was led by Eddis Sami bin Khemais and that he was linked to al-Qaeda.
However, bin Khemais was sentenced last December to four and a half years in prison for association in producing counterfeit documents and involvement in illegal immigration to Italy.
Terrorism charges were dropped against him.
Dozens of Muslims have been arrested in Italy since the 11 September attack on suspicion of links to organisations regarded by the authorities there as terrorist.
Most of them, however, have been released for lack of evidence.
Under Italian law, even if some of the suspects may prove to be innocent, all can be held for months until authorities investigating a particular incident identify those responsible.