Threats from the Islamic State are forcing the U.S. military to recalculate how to get Americans to the Kabul airport, the Associated Press reports, citing government sources. The State Department published a security warning Saturday advising Americans not to come to the airport without direct instruction to do so from a government official. AP reports that ISIS has made threats against Americans, leading military commanders to issue specific instructions to small groups of Americans and other evacuees on how to reach the airport via specific transit points. The threats throw yet another wrench into an already chaotic scene at Hamid Karzai airport, which has been the final stage in the dramatic U.S. withdrawal from Afghanistan and subsequent Taliban takeover.