LONDON  - The battle against ‘poisonous’ extremism must be fought for years in North Africa with ‘an iron resolve’, British prime minister David Cameron has said, as he warned that Al-Qaeda’s main threat has begun to shift from Afghanistan and Pakistan.The attack upon the Algerian gas plant, which was finally brought to an end on Saturday, underlined “the threat that terrorist groups pose to the countries and the people of that region – and to our citizens, our companies and our interests too,” he told MPs.“We are in the midst of a generational struggle against an ideology which is an extreme distortion of the Islamic faith and which holds that mass murder and terror are not only acceptable but necessary.“We must tackle this poisonous thinking at home and abroad and resist the ideologues’ attempt to divide the world into a clash of civilisations,” the prime minister said.“But as it escalates it is also becoming a magnet for jihadists from other countries who share this poisonous ideology,” he said, before adding that the international response “must be one that is tough, intelligent, patient and based on strong international partnerships”.Cameron’s speech was immediately compared with ones given a decade ago by his Labour predecessor, Tony Blair, but No 10 stressed Mr Cameron’s emphasis on international co-operation rather than unilateral action.“Our tough security response must be matched by an intelligent political response. Al-Qaeda franchises thrive where there are weak political institutions, political instability and the failure to address long-standing political grievances,” he said.Though Cameron has been praised for his handling of the crisis, it is clear that the families of some of the dead are bitterly unhappy about the amount of information that they received from the Foreign Office during the hostage crisis.Bob Whiteside said he had found out that his brother, Kenny, had been killed after an Algerian colleague had posted a message on Facebook.Police called to his home on Saturday night to confirm that his brother, who had lived in Johannesburg, was among the dead.However, No 10 Downing Street and the Foreign Office have cautioned from the beginning that information has been difficult to secure from the remote gas plant.“There is still some uncertainty around the precise facts,” Cameron cautioned MPs.