CAMP BASTION, Afghanistan (CNN) – The United States must learn from a series of crises in Afghanistan so it does not repeat them, the U.S. defense secretary told American troops in the country Wednesday, days after an American soldier was detained on suspicion of killing 16 Afghan men, women and children.
Leon Panetta said the killings Sunday, as well as the accidental burning of Qurans by U.S. troops last month and deadly riots that resulted, were “deeply troubling.”
“We have to learn the lessons from each incident so we do everything possible they don’t happen again,” Panetta said, adding that the “tragic” incidents “do not define the relationship between the coalition forces and the Afghan people.”
Panetta flew into Afghanistan Wednesday, making him the first high-ranking American official to visit the country since the weekend shooting rampage being blamed on an American soldier.
Panetta’s two-day trip was scheduled long before the killing spree.
The defense secretary is due to meet with Afghan tribal leaders and government ministers, but his schedule does not include a trip to the area of Kandahar province where the killings took place.
About the same time Panetta landed in Afghanistan, a “stolen vehicle incident” took place at Camp Bastion, NATO’s International Security Assistance Force said in a statement.
One coalition service member was injured, and “the alleged perpetrator was apprehended by base security personnel.” ISAF did not provide details but said it was investigating.
“At no point was the secretary or anyone on the aircraft in any danger from this incident,” ISAF said.
Also Wednesday, a huge explosion killed eight people in Helmand province, which Panetta was visiting, but he was not affected.
The massive roadside blast ripped through a minivan, leaving its victims unrecognizable, the Helmand government said. The government blamed “terrorists” for the bombing.
In a separate incident, a motorcycle bomb exploded in Kandahar, killing an Afghan intelligence agency security guard who was trying to defuse it, a government media agency said. Three others, including a civilian, were injured. It was unclear if the bombing was related to Sunday’s killings.
The Taliban have threatened to behead Americans in response to the shootings, and Afghan officials have expressed outrage about them, with President Hamid Karzai calling them “acts of terror and unforgivable.”
Despite some protests and local violence, the country has not erupted the way it did last month when American troops burned copies of the Quran and other Islamic religious materials. Military officials said the materials had been seized from Afghan prisoners because they contained extremist messages.
President Barack Obama called that incident a mistake and apologized for it, but those efforts did not head off riots and reprisal attacks that left at least six American troops and dozens of Afghans dead.
Panetta’s first stop in Afghanistan was at Camp Bastion and the adjoining base Camp Leatherneck, where he met top U.S. and British military leaders and spoke to a group of about 200 troops. From there, he will travel to a nearby forward operating base to meet more coalition troops before flying to Kabul.
His arrival comes a day after Afghan forces came under fire during a funeral for victims of the shooting rampage, while protesters angered by the killings blocked a major highway in the country’s southeast.
In Washington, Obama said Tuesday that American officials were “heartbroken” by the deaths but had no plans to change course in the decade-old war in Afghanistan.
Sunday’s predawn rampage, which left nine children, three women and four men dead in two villages in rural Kandahar province, has added to the strain between Washington and Kabul.
The Taliban have battled U.S. and NATO troops as well as Afghan government forces since the 2001 invasion after the September 11 attacks. Following Sunday’s killings, they described U.S. troops as “sick-minded American savages.” In a statement Tuesday, they said they would take revenge “by killing and beheading Americans anywhere in the country.”
The U.S. military said 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 and returning alone to the base.
There is another image showing him lying prone in a field. A separate military source said there is imagery showing the suspect “low crawling” through the area outside the base. The image was collected from what the official described as an aerial asset.
The suspect then is shown getting up and walking back to the outpost, according to a senior U.S. military official with direct knowledge of the information.
The arrival and departure images were taken by base surveillance cameras.
A military search party was put together to look for the missing soldier, but it’s unclear to what extent searchers got under way before he returned to the base, the official said.
The soldier, whom the military has not named, has yet to be charged. He turned himself in to his fellow Americans after the killings and could face the death penalty, Panetta has said. Afghanistan’s parliament has demanded a public trial for the suspect, but U.S. officials said they will handle the investigation and prosecution themselves.
The officials have described the suspect as a staff sergeant from an infantry unit assigned to support Special Forces troops in Kandahar province, the Taliban heartland and a leading focus of the U.S.-led counterinsurgency strategy in Afghanistan.
Military authorities have presented a determination of probable cause to allow them to keep the sergeant in detention, an International Security Assistance Force official told CNN.
Investigators are looking into whether alcohol may have been a factor in the attack. Toxicology tests on the suspect are not complete, the two senior military officials said.
The suspect served three tours of duty in Iraq before being deployed to Afghanistan, according to the U.S. military.
During the suspect’s last deployment, in 2010, he was riding in a vehicle that rolled over in a wreck, according to a senior Defense Department official, who also spoke on condition of anonymity. After the wreck, the sergeant was diagnosed with traumatic brain injury but was treated and then found fit for duty, the official said.
Speaking Tuesday at the White House, Obama said he has told Karzai that the United States “takes this as seriously as if it was our own citizens and our own children who were murdered.”
“The killing of innocent civilians is outrageous and it’s unacceptable. It’s not who we are as a country and it does not represent our military,” he said. A U.S. military investigation “will follow the facts wherever they lead us, and we will make sure that anybody who was involved is held fully accountable with the full force of the law,” he added.
CNN’s Larry Shaughnessy and Sara Sidner and journalist Ruhullah Khapalwak contributed to this report.
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