Officials plan to focus on whether the Army had intelligence that the Taliban might attack in Wanat, a village in Kunar Province on the Pakistani border, CNN reported. They will also look at whether any intelligence was available to the coalition forces at the base near Wanat.

The Taliban did not get into the main base Sunday. But the U.S. military pulled out Wednesday, and the Taliban quickly occupied the base, The Times of London reported.

The soldiers who were killed Sunday were with Afghan troops looking for a site for a remote observation post. U.S. forces in Afghanistan have not lost that many soldiers in one incident in three years.

In the past two months, more U.S. soldiers have been killed in Afghanistan, where fighting has picked up, than in Iraq. The Defense Department is considering an increase in troop strength in Afghanistan.