Bin Laden warns US not to kill alleged 9/11 chief March 25, 2010 at 12:01 PM CDT - Updated June 19 at 11:10 PM CAIRO (AP) - Al-Qaida leader Osama bin Laden has threatened to kill any captured Americans if the U.S. executes the alleged mastermind of Sept. 11. In a new audio message aired on Al-Jazeera TV Thursday, bin Laden said if the U.S. executes Khalid Sheik Mohammed that it would mean a "death sentence" for Americans captured by al-Qaida. Mohammed is currently in U.S. custody. The Obama administration is still debating where to hold his trial. Copyright 2010 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.