The suspects allegedly belong to Adl Wal Ihsan ('Justice and Charity') a highly secretive group. Its alleged members used psychological and physical violence to teach their children to hate western culture and customs as well as all religions other than Islam, according to investigators.
Adl Wal Ihsan was founded in 1973 by Moroccan fundamentalist Abdessalam Yassine Yassin and proselytises in Morocco's universities. In recent years it has also targeted Moroccan immigrants living in Europe and North Africa. Although Yassin has Republican sympathies, his movement is tolerated in Morocco, a monarchy, but police have stepped up surveillance of the group.
As long ago as November, 2009, Italy's interior minister Roberto Maroni said the attention of Italian security forces was focused on the northern city of Milan and the surrounding Lombardy region "where the phenomenon of terrorism is on the rise."
Maroni's comments came after Italy's first would-be suicide bomber, the Libyan Muslim immigrant Mohammed Game made a botched attempt to blow up a military barracks in Milan in October 2009.
Game and two accomplices were jailed in July 2010 for the failed bombing, in which he was blinded and lost part of a hand and an Italian soldier was slightly wounded.
Game's case renewed concern about the integration of immigrants. He had lived in Italy for many years, has an Italian partner and three children.