Washington ? U.S. authorities believe they have the al-Qaida leader Abu Zubaydah in custody, a U.S. official said Sunday. He would be the highest-ranking leader in the terrorist organization to fall into American hands since the Sept. 11 attacks.

Zubaydah is one of Osama bin Laden’s senior operational planners. When bin Laden and his inner circle would call for an attack, Zubaydah would contact the cells in the field to conduct them, authorities have said.

He is known to have organized several attacks on U.S. interests, U.S. officials say.

Officials said his capture could disrupt new terrorist attacks in the works.