Soldier could face death penalty in Afghan killings

Kabul, Afghanistan (CNN) -- The U.S. Army soldier accused of killing 16 Afghan men, women and children in a house-to-house shooting rampage could face the death penalty, Defense Secretary Leon Panetta said.

Panetta spoke to reporters as he flew to the Central Asian nation of Kyrgyzstan for high-level talks Tuesday.

Hundreds of Afghans took to the streets Tuesday to protest the killings as the Taliban threatened to behead "Americans anywhere in the country."

An American sergeant is suspected of shooting nine children, three women and four men in two villages near his combat outpost in southern Afghanistan on Sunday. He turned himself in after the killings, the military said. The Army's Criminal Investigation Command is leading the investigation. The suspect has not been charged.

In Jalalabad, near the border with Pakistan, "hundreds of protesters, many of whom are university students, have taken to the streets," said Ahmad Zaii Abdulzai, a spokesman for Nangarhar province.

Leaders from across Afghanistan's fragmented political terrain have expressed anger and outrage over the attack in the district of Panjwai in Kandahar province.

Karzai has condemned the weekend bloodshed as "unforgivable." Afghanistan's parliament has demanded a public trial for the suspect, and the Afghan Taliban have described U.S. troops as "sick-minded American savages" and vowed to exact revenge.

In a new statement Tuesday, the Taliban said the group would take revenge "by killing and beheading Americans anywhere in the country."

There are fears that Sunday's killings could reignite the anger that led to deadly riots directed at international forces last month over the burning of Qurans by U.S. troops. That was one of a string of incidents involving American forces that have strained ties between the United States and Afghanistan.

U.S. commanders were forced to condemn a video of a squad of Marines urinating on bodies in January, and several soldiers -- from Joint Base Lewis-McChord in Washington state, like the suspect in Sunday's shooting -- were charged with taking part in a rogue "kill squad."

Sunday's killings have brought a deluge of high-level statements from Washington expressing shock, sadness and insistence that the U.S. mission in Afghanistan would stay on course.

As he set out for a trip to the Middle East on Monday, Panetta said the United States and its NATO allies "seem to get tested almost every other day." But he added, "It is important that, all of us, United States, Afghanistan, the (NATO-led) forces all stick to the strategy that we've laid out."

"War is hell," he said. "These kind of events and incidents are going to take place. They've taken place in any war. They're terrible events. This is not the first of those events, and they probably won't be the last."