KABUL - Gunmen killed 10 members of a medical team, including six Americans, traveling in the rugged mountains of northern Afghanistan, demonstrating the reach of insurgents far from their traditional havens and shocking the expatriate community here.
The attack was one of the deadliest on civilian aid workers since the war began in 2001. That it occurred in Badakhshan province, a scenic mountain redoubt considered a peaceful refuge from the war, added to growing concern that the Taliban has seized on northern Afghanistan as its latest front.
The dead have not been officially identified, and the bodies not yet returned to Kabul, but Afghan and Western officials said the victims were thought to be members of a medical team working with a Christian charity group that has decades of experience in Afghanistan.
That team, from the International Assistance Mission, lost contact with its office in Kabul on Wednesday, two days before the attack, said Dirk Frans, the group's executive director.
"We've got a team that has gone missing, and then there are 10 people found dead. At the moment we're working on the assumption that this is the same team," Frans said.
The Taliban quickly asserted responsibility for the killings, saying the medical workers were "foreign spies" and were spreading Christianity. But police officials have not ruled out robbery as a motive, as the victims was stripped of their belongings after they were shot.
The team members - six Americans, one German, one Briton and four Afghans - were returning from neighboring Nurestan province, where they had spent several days administering eye care to impoverished villagers. They were traveling unarmed and without security guards, Frans said.
The dead are thought to include the team's leader, Tom Little, an optometrist from New York who had worked in Afghanistan over the past four decades.
Three of the victims are thought to be women, including Karen Woo, a British surgeon who had written on her blog about the possible risks of traveling to the area.
Two of the Afghans were unharmed.
The group is registered as a Christian nonprofit organization. Although its members do not shy away from this affiliation in this conservative Muslim country, Frans and others said they do not proselytize.
In their work since 1966 on health and economic development projects, under King Zahir Shah, the Russians, the mujaheddin government and the Taliban, Frans said, "all along we've been known as a Christian organization. That has been a nonissue."
"This is truly a bedrock institution in Afghanistan," said Andy Campbell, the Afghanistan country director for the National Democratic Institute. "They have been around for decades."
Others who have worked with the group described it as culturally sensitive to the Muslim values of Afghanistan and staffed by foreigners committed to long-term development work in the country. "This is not a Mickey Mouse organization," said a person who has worked for and evaluated the organization's projects in the past.
The Taliban has targeted foreign aid workers in the past but such attacks are relatively rare, and insurgents have allowed some aid groups safe passage into areas they control. In August 2008, gunmen killed three women from the International Rescue Committee and their Afghan driver in Logar province. Four years earlier, 11 Chinese road workers were shot to death in Kunduz province.
Among the confusing aspects of the attack was why the Taliban, if indeed responsible, chose to summarily execute the team, rather than hold them hostage, which it has done in many other cases to bargain for money or other concessions. In July 2007, the Taliban seized 23 South Korean missionaries driving in a bus from Kandahar to Kabul. Two of the hostages were killed before the South Korean government negotiated the release of the others.
The exact timing of the attack remained unclear Saturday. The deputy police chief in Badakhshan, Gen. Sayid Hussain Safari, said insurgents might have followed team members on their return hike and attacked as they reached their vehicles.
Safari said 10 gunmen surrounded the medical team, shot the victims with AK-47s, and ransacked their belongings from the vehicles. Of the 11 people at the scene of the shooting, only one survived, an Afghan driver named Saifullah. He told police that the gunmen led him on a long march uphill as he recited the Koran and prayed to be spared.
"He swore to God and said that I'm a true Muslim. That's why they trusted him and released him," Safari said.
But his escape has raised suspicion among some close to the medical team that he might have been involved in orchestrating the attack. Saifullah, who remains in the custody of district police, has not yet been interrogated by the provincial authorities and could not be reached for comment.
Badakhshan is a scenic province far from the insurgent hot spots in southern and eastern Afghanistan. But insurgents have become more prevalent there and in other northern provinces over the past year as they have shifted to areas with fewer NATO troops. Military officials have said the area is also an important point for manufacturing heroin and transporting it out of Afghanistan.
• Special correspondent Javed Hamdard contributed to this report.