WASHINGTON — The Army said Wednesday that 7,000 family members of soldiers killed in the Iraq or Afghan wars mistakenly were sent letters addressing them as "John Doe."

Army Chief of Staff Gen. George W. Casey Jr. was sending a personal letter to all the families who received the improperly addressed letters as the result of a printing error, the Army said.

The 7,000 original letters were sent late last month to inform survivors about private organizations that offer gifts, programs and other assistance to families that have lost soldiers in Iraq or other countries where they are deployed for the war on terrorism.

It was sent from the U.S. Army Human Resources Command's Casualty and Mortuary Affairs Center in Alexandria, Va., which issued a formal apology Wednesday.

The letters, which were printed by a contractor, were to have been automatically addressed with the specific names and addresses of survivors, said Paul Boyce, an Army spokesman. Instead, they contained the placeholder greeting — "Dear John Doe."

"It's our fault for not catching it," he said. "We are certainly sorry."

The Washington Post quoted Merrilee Carlson, whose son, Sgt. Michael Carlson, died in Baqubah, Iraq, on Jan. 24, 2005, as saying, "The indication that anyone would perceive that a hero is not significant, that they would not direct this personally to them, is shattering. While it's a simple mistake, it's a very tragic mistake."

The Post reported that Carlson said she is contacting other Army Gold Star mothers — a designation for mothers of troops who died in military service — to warn them about the letter and explain that it was a mistake.

"The Army treasures its heroes, and they will work hard to make sure it never happens again," said Carlson, president of Families United for Our Troops and Their Mission, a Washington-based nonprofit coalition that includes family members of fallen troops and supports the mission of building democracy in the Middle East.

Casey's personal note to the families alluded to the fact that he lost his own father in Vietnam and it said the Army is extremely sensitive to family grief.

An apology also was being posted on the human resources Web site, Boyce said.

"There are no words to adequately apologize for this mistake or for the hurt it may have caused," Brig. Gen. Reuben D. Jones, the Army adjutant general, said in the statement to be posted.

Boyce said all the other information in the letter regarding the assistance organizations was correct.

"It is important the original intent of the letter is not lost," Jones' statement said. "The organizations mentioned are dedicated to honoring loved ones and recognizing their sacrifice and commitment."