Bring home bin Laden's head, CIA told

US spy chiefs ordered agents to deliver Osama bin Laden's severed head in a box of dry ice and hoist heads of other al-Qaeda leaders on pikes, a retired field officer has disclosed.As the US reeled in shock days after the September 11 attacks in 2001, former CIA officer Gary Schroen was sent to Afghanistan to help the opposition Northern Alliance to topple bin Laden's hosts the Taliban.