Members of a suspected militant Islamist cell arrested this week in Spain were trying to obtain explosives to bomb a Jewish bookshop in Barcelona, an investigating magistrate said on Friday. Other potential targets of the group included synagogues and public buildings in the Catalonia region, the magistrate said in a report after receiving information from prosecutors. The report said seven of the 11 people arrested on Wednesday in northeastern Catalonia have been put under formal investigation - a step just short of being charged - and will be held in custody awaiting trial, it added.