BAGHDAD (AP) — The U.S. military says an American solider has been killed in southern Iraq.

The military said in a statement the solider was killed Sunday while conducting operations in Iraq’s southern province of Basra.

It was not immediately clear whether the soldier died as a result of hostile fire. The statement provided no details about the incident, saying only that it is under investigation.

This is the first fatality among U.S. troops in Iraq since the last American combat unit left the country earlier this week.