Obama: "As if it was our own citizens ... who were murdered."

President Obama spoke briefly Tuesday in response to the early-morning killings of Afghan civilians by a lone U.S. soldier in Kandahar Province.

The Star Tribune reports Obama as saying "The United States takes this as seriously as if it was our own citizens, and our children, who were murdered."

In total, 16 civilians were murdered, three of whom were children, reports the Star Tribune.

Sara Sidner, writing for CNN, reported that the suspect, as yet unknown to the public, has turned himself in, and that the case will be handled by the military. In addition, she wrote, citing comments by Defense Secretary Leon Panetta, the case may result in the death penalty.

Remarks made by Panetta and published by CNN point to growing concern about the situation in Afghanistan.