BAGHDAD — American casualties in Iraq are mounting as U.S. and Iraqi forces have stepped up a block-by-block battle to loosen the grip of militia violence on Baghdad. At least 19 American soldiers have been killed in combat since Saturday, many of them in the capital, according to the Defense Department. ‘This has been a hard week for U.S. forces,’ said Maj. Gen. William Caldwell, the top U.S. military spokesman in Iraq. ‘We are all looking at that and are very much aware of it.’ Four U.S. soldiers were killed by small-arms and indirect fire northwest of Baghdad on Wednesday. Indirect fire can refer to mortars or rockets. Eight American troops were killed in firefights and bombings Monday in Baghdad. It was the deadliest single day in the capital since July 2005. U.S. and Iraqi forces are engaged in a high-stakes fight in Baghdad to clear out militias and insurgents. ‘Certainly with this operation, we’re hitting close to home and infringing on their freedom of movement and their ability to conduct these types of activities,’ said Lt. Col. Michelle Martin-Hing, a U.S. military spokeswoman in Iraq. ‘What we’re seeing now is some push-back.’ The increased […]