WASHINGTON (AP) - As Afghanistan sees its first significant protest over Sunday's killings of 16 civilians, allegedly by a U.S. soldier, President Barack Obama is promising an investigation that will "follow the facts wherever they lead us."

Students in eastern Afghanistan staged a demonstration today in response to the killings. And the Taliban are claiming responsibility for an attack today on a government delegation that was visiting the villages where the shooting deaths took place.

Speaking at the White House, Obama says the killings do not reflect American values or the U.S. military. He called the incident tragic and heartbreaking, but he insists it won't change U.S. commitment to finishing the job in Afghanistan.

Obama says the U.S. will "responsibly" draw down its forces between now and the end of 2014, the date he set with allies to close out the war.