The US Army's First Cavalry Division has taken control of security in Baghdad.
The unit steps into a dangerous role that had been the duty of the Fourth Infantry Division -- a unit that had been caught in spiraling violence in the capital as part of an operation designed to have the opposite effect.
There are currently 152,000 US troops in Iraq and several divisions have held authority over Baghdad since it was captured by US troops in April of 2003.
(Copyright 2006 by The Associated Press. All Rights Reserved.)