The spiritual guide for Iranian-backed guerrillas holding foreign captives in Lebanon was quoted as saying Tuesday that the hostages should not suffer because the U.S. Navy shot down an Iranian jetliner. But an anonymous caller in Beirut purporting to speak for Islamic Jihad, which holds Americans Terry Anderson and Thomas Sutherland, threatened to kill one of them in revenge for Sunday's attack. The caller did not elaborate, and it was not possible to authenticate the call. Islamic Jihad has said it would authenticate its written statements with photographs of hostages. "I find no justification for making the hostages account for a matter with which they have no link," Sheik Mohammed Hussein Fadlallah said in an interview with the Sohofiya News Agency, a Lebanese newsletter based in west Beirut. "There's no link between this subject (the hostages) and the shooting down of the plane."