The US Army is to apologise to the families of officers killed or wounded in action who were sent letters urging them to return to active duty.
The letters were sent to more than 5,100 Army officers listed as recently having left the military.
But this figure included about 75 officers killed in action and about 200 wounded in action.
More than 3,000 members of the US military have died in Iraq since the war began.
Casualties have also been suffered in Afghanistan since the US invasion.
"Army personnel officials are contacting those officers' families now to personally apologise for erroneously sending the letters," the army said in a statement.
It said the database normally used for such correspondence with former officers had been "thoroughly reviewed" to remove the names of dead and wounded soldiers.
"But an earlier list was used inadvertently for the December mailings," it added.