Dec 4 (Reuters) - Four U.S. troops were killed in Iraq on Sunday when a Marine helicopter with 16 people aboard suffered mechanical failure and made an emergency landing in a lake, the military said on Monday. Following are the latest figures for military deaths in Iraq since the U.S.-led invasion in March 2003: U.S.-LED COALITION FORCES: United States 2,904 Britain 126 Other nations 121 IRAQIS: Military Between 4,900 and 6,375# Civilians Between 49,235 and 54,615* # = Think-tank estimates for military under Saddam Hussein killed during the 2003 war. No reliable official figures have been issued since new security forces were set up in late 2003. * = From www.iraqbodycount.net, run by academics and peace activists, based on reports from at least two media sources. The IBC says on its Web site that the figure underestimates the true number of casualties.
