Editor's Note: This post has been updated to reflect that 30 American troops were killed in the attack, rather than 31, as initially reported.

Taliban insurgents shot down an American military helicopter in Afghanistan Saturday, killing 30 American troops, 7 Afghan commandos, and an interpreter multiple news outlets are reporting.

The helicopter was shot down with a rocket-propelled grenade just outside of Kabul, according to one Western military official. The Taliban has officially taken credit for the attack.

The AP reports most of those killed were part of Navy SEAL Team 6, the elite special operations unit responsible for hunting down Osama bin Laden in May.

The downing of the U.S. Chinook helicopter resulted in the largest loss of American life in a single incident during the war in Afghanistan.

The attack also represents a blow to the relative peace American soldiers have been trying to keep as the U.S. and NATO begin drawing down military forces in Afghanistan.

President Barack Obama offered condolences to the families of those who died. "Their death is a reminder of the extraordinary sacrifice made by the men and women of our military and their families,” Obama said.