WASHINGTON (Reuters) - The U.S. Army apologized on Wednesday for sending 7,000 letters addressed to “Dear John Doe” to the relatives of U.S. soldiers killed in Iraq and Afghanistan.

The letters, printed by a contractor and mailed in December, were intended to inform family members about private organizations that offer assistance to those who have lost relatives in Operation Iraqi Freedom and Operation Enduring Freedom.

The Army said the letters should have contained specific salutations and addresses, instead of the anonymous greeting. It blamed a printing error for the mix-up.

“The U.S. Army is apologizing,” the armed service said in a statement.

Gen. George Casey, the Army chief of staff, will send a personal letter to each person who received improperly addressed correspondence, the Army said.

The U.S. Army Human Resources Command’s Casualty and Mortuary Affairs Center, which issued the letters, formally apologized on Wednesday.

“There are no words to adequately apologize for this mistake, or for the hurt it may have caused,” said Brig. Gen. Reuben Jones, the Army’s adjutant general.

“It is important the original intent of the letter is not lost. The organizations mentioned are dedicated to honoring loved ones and recognizing their sacrifice and commitment.”

About 4,224 U.S. service members have died in Iraq since the U.S.-led invasion in March 2003. Another 627 have died in Operation Enduring Freedom, which includes military operations in Afghanistan as well as other countries in Africa, Asia and the Middle East.