Falluja: US vows revenge

US troops on Thursday vowed to use overwhelming force to enter Falluja and hunt down those who killed and mutilated four American contractors.

Marines took up positions on the outskirts of the town where insurgents ambushed the contractors on Wednesday, but the US Army’s deputy director of operations Brigadier General Mark Kimmitt said they would return.

‘‘Coalition forces will respond,’’ Kimmitt told a news conference. ‘‘They are coming back and they are going to hunt down the people responsible for this bestial act. It will be at a time and a place of our choosing. It will be methodical, it will be precise and it will be overwhelming.”