Kabul, Afghanistan (CNN) -- Afghan forces came under fire Tuesday during a funeral for victims of a weekend rampage blamed on a U.S. soldier, while protesters angered by the killings blocked a major highway in the country's southeast. The U.S. military says the Army sergeant blamed for the killings acted alone. Two senior military officials told CNN that images from security cameras around his outpost showed the suspect leaving the base alone and returning alone. In Washington, U.S. President Barack Obama said American officials were "heartbroken" by the deaths but have no plans to change course in the decade-old war in Afghanistan.
@highlight
Security cameras show the suspect leaving and returning alone, officials say
@highlight
"The killing of innocent civilians is outrageous," Obama says
@highlight
An Afghan official at a funeral for a shooting victim hears gunfire
@highlight
The Taliban say the deaths will be avenged by "beheading" Americans
U.S.
U.S.
U.S.
American
Americans
After Sunday's killings, they described @placeholder troops as "sick-minded American savages."
U.S.
U.S.
U.S.
American
Americans
After Sunday's killings, they described U.S. troops as "sick-minded @placeholder savages."
U.S.
U.S.
U.S.
American
Americans
In a new statement Tuesday, they said they would take revenge "by killing and beheading @placeholder anywhere in the country."
U.S.
U.S.
U.S.
American
Americans
Afghanistan's parliament has demanded a public trial for the suspect, but @placeholder officials said they will handle the investigation and prosecution themselves.