Osama Bin Laden threatened to execute any Americans taken prisoner by al-Qaida if Khalid Sheikh Mohammed, the alleged mastermind of the Sept. 11 attacks, is executed, pan-Arab al-Jazeera television reported Thursday.

Bin Laden said in a new audio message that the day the U.S. takes the decision to execute Sheikh Mohammed and his co- inspirators, al-Qaida "would also take the decision that any of you falling into our hands will be executed."

Sheikh Mohammed is accused of masterminding the Sept. 11, 2001 attacks on New York and Washington that took nearly 3,000 lives, which sparked wars in Afghanistan and Iraq and prompted former U.S. President George W. Bush's war on terror.

The alleged architect of terror was captured in Pakistan in 2003.