Interrogations of suspects in Pakistan lead its investigators to believe that the alleged plot to blow up US-bound jetliners was sanctioned by the al-Qaida leadership, a senior intelligence official told The Associated Press Thursday. The terror group's No. 2 leader Ayman al-Zawahri probably cleared the plot, the official said on condition of anonymity because of the sensitivity of the ongoing investigation. The latest investigations by Pakistan also indicate that a British national arrested in Pakistan, Rashid Rauf, planned the plot and recruited people in Pakistan. He had also made contacts with people in Britain to take part, the official said.