WASHINGTON—The U.S. secretly warned Iran that Islamic State was preparing to carry out the terrorist attack early this month that killed more than 80 Iranians in a pair of coordinated suicide bombings, U.S. officials said.
The confidential alert came after the U.S. acquired intelligence that Islamic State’s affiliate in Afghanistan, ISIS-Khorasan, known as ISIS-K, was plotting to attack Iran, they said.
American officials said the information passed to Iran was specific enough about the location and sufficiently timely that it might have proved useful to Tehran in thwarting the attack on Jan. 3 or at least mitigating the casualty toll.
