Ten members of a medical team, including six Americans, were shot and killed by militants as they were returning from providing eye treatment and other health care in remote villages in northern Afghanistan, a spokesman for the team said Saturday. Dirk Frans, director of the International Assistance Mission, said one German, one Briton and two Afghans also were part of the team that made the two-week trip to Nuristan province. They drove to the province, left their vehicles and hiked for hours over mountainous terrain to reach the Parun valley in the province's northwest. Taliban spokesman Zabiullah Mujahid said in Pakistan that they killed the foreigners because they were “spying for the Americans” and “preaching Christianity.” Frans said the International Assistance Mission is registered as a nonprofit Christian organization but does not proselytize. “This tragedy negatively impacts our ability to continue serving the Afghan people as IAM has been doing since 1966,” the charity said in a statement. “We hope it will not stop our work that benefits over a quarter of a million Afghans each year.” The team, made up of doctors, nurses and logistics personnel, was attacked as it was returning to Kabul after the two-week mission in Nuristan, Frans said. They had decided to travel through Badakhshan province to return to the capital because they thought it would be the safest route, Frans said.