WASHINGTON, July 13 (Xinhua) -- The Pentagon confirmed on Friday that one U.S. soldier was killed in an incident that occurred in eastern Afghanistan on Thursday, the second death of a U.S. soldier in Afghanistan within a week.

The soldier died of "wounds sustained as a result of enemy small arms fire while conducting operations in support of a medical evacuation landing zone in Zurmat district, Paktiya province," said the Pentagon in a statement.

The incident is under investigation, the statement said.

The Pentagon on Sunday identified a U.S. soldier who was killed Saturday in what it called an apparent insider attack in Afghanistan.