A U.S. service member was killed and two others wounded in what NATO is calling "an apparent insider attack" in Afghanistan Saturday.Details of the incident, which is under investigation, were not immediately released.The identity of the service member who was killed will not be released until 24 hours after the next of kin has been notified, which is the policy of the U.S. Defense Department, NATO said in a statement.NATO said the wounded service members are in stable condition. Copyright 2018 NPR. To see more, visit http://www.npr.org/.