Pakistan has unleashed its police and intelligence services to track down links to the London terror bombers, and has found connections. However, the links appear to be mainly with Madrassas (religious schools), which some conservative Anglo-Pakistani families send their children to for a few years, to insure that the kids gain more language and cultural skills from the old country. The kids often pick up Islamic radical attitudes, which these days often means Islamic terrorism, and bring it back to Britain with them. The government has backed off on trying to get the Madrassas out of  terrorist business because of  the potential political backlash.