BAGHDAD (AFP) - The remains of four American security contractors ambushed in Iraq (news - web sites) were recovered as US officials vowed to exact vengeance for their gruesome murder. US Brigadier General Mark Kimmitt, deputy head of coalition operations, said the remains were handed over to US forces Thursday. The four, employees of the private US firm Blackwater Security Consulting of North Carolina, were killed Wednesday in an ambush and their vehicles set ablaze in Fallujah, 50 kilometers (30 miles) west of Baghdad. Two of the charred bodies were then dismembered and publicly paraded as a gleeful mob cheered...