The Army said Friday it would apologize to the families of about 275 officers killed or wounded in action who were mistakenly sent letters urging them to return to active duty. The letters were sent a few days after Christmas to more than 5,100 Army officers who had recently left the service. Included were letters to about 75 officers killed in action and about 200 wounded in action. The 75 represent more than one-third of all Army officers who have died in Iraq since the war began. The Army did not say how or when the mistake was discovered. It said the database normally used for such correspondence with former officers had been "thoroughly reviewed" to remove the names of wounded or dead soldiers. "But an earlier list was used inadvertently for the December mailings," the Army statement said, adding that the Army is apologizing to those officers and families affected and "regrets any confusion."