MADRID (AFP) - An Al-Qaeda suspect plotted to poison tourists' water supplies to avenge the killing of Osama bin Laden, a Spanish judge said Saturday as he remanded the man in custody. Abdellatif Aoulad Chiba, a 36-year-old Moroccan, had gone so far as to obtain manuals on poisons, toxins and explosives on militants websites, the judge said. Police swooped soon after the suspect appeared to be saying farewell to his wife. Chiba's online comments on the websites "expressed a clear desire to carry out an attack against 'infidels' by poisoning human water supplies", he said in a written ruling. The online comments indicated that he wanted to strike "at camp sites and tourist resorts", most likely in Spain, said the judge of the National Court, Spain's highest authority for hearing terrorist cases. "The risk increased after he entered in contact with other users of the forum who supplied him with manuals on how to make and use poisons, toxins and explosives." Police arrested Chiba on Wednesday in the southern town of Linea de la Concepcion. He was remanded in custody Saturday on suspicion of conspiracy to commit a terrorist killing and of being a member of a terrorist organisation. Formal charges have not yet been laid. In one online post found by police he swore his allegiance to Al-Qaeda's North African offshoot, Al-Qaeda in the Islamic Maghreb. The suspect had "expressed his intention to continue the organisation's efforts to avenge the death of Osama bin Laden and other key members of Al-Qaeda," the court said. US forces killed bin Laden on May 1 in Pakistan, a decade after the September 11, 2001 attacks he masterminded leveled the World Trade Center in New York and damaged the Pentagon. "It is considered probable that all the actions carried out by Abdellatif Aoulad could be the steps taken according to a plan whose goal could be to carry out a terrorist act," the judge said. Chiba called for attacks to be carried out in Europe and the United States in the online postings but the court said the plot to poison water supplies "probably concerned Spain since that is where he lives". Police found information about poison and water deposits on his computer, the court said. Chiba telephoned his wife in Girona, northeastern Spain, in the early hours of August 12, the ruling said. "During the conversation he did not discuss any topic which would justify the urgency of calling at this hour," the court said. "But between the lines you can detect a need to express his love in what appeared to be a tacit farewell." Al-Qaeda in the Islamic Maghreb claims allegiance to the global extremist network. It carries out attacks and kidnappings and runs smuggling routes in the Sahel region that spans north Africa. Spain suffered its worst terror attack on March 11, 2004 when bombs exploded on packed commuter trains in Madrid, killing 191 people and wounding 1,841 others in a strike by a local cell of Islamic extremists carried out in the name of Al-Qaeda. Twenty-one people, mostly Moroccans, were convicted of involvement in the attacks.