WASHINGTON (Reuters) - The United States believes that three adults besides Osama bin Laden were killed in Sunday's raid in Pakistan and that one of the dead was an adult son of bin Laden, a senior Obama administration official said.

An official also said bin Laden's death puts al Qaeda on a path of decline that will be difficult to reverse.

(Reporting by Patricia Zengerle and Alister Bull, editing by Mohammad Zargham)