FBI investigators have made new arrests and developed leads that reinforce concerns that terrorists plan to strike around the US presidential election. However, the CIA has discredited one person who told its agents of such a plot involving al-Qaeda. A senior FBI official, speaking on condition of anonymity, today said some of the leads were culled from interviews with thousands of individuals that agents had conducted in the Muslim community. The official would not be more specific, but said the FBI continued to have misgivings about possible al-Qaeda intentions to launch an attack with the goal of affecting the elections....