BAGHDAD, Iraq (AP) - American troops killed hundreds of insurgents in and around Baghdad in fighting over the past week, but have more work to do to fully secure the city and roads to the south and west that are vital for U.S. supply transport, a top U.S. military official said Monday. In the heaviest battles seen in the capital since the fall of Saddam Hussein a year ago, U.S. troops battled Sunni insurgents on the western edge of Baghdad - at one point for nearly 72 hours straight - and fought rebellious Shiite militiamen in a densely populated neighborhood...