KABUL (Reuters) - An international Christian aid group on Monday played down claims by the Taliban they had killed 10 members from one of the group's medical teams, saying it was still unclear who was responsible.
Dirk Frans, executive director of the International Assistance Mission (IAM), also told a news conference that an Afghan driver who was with the team was in custody at the Interior Ministry in Kabul.
He did not say if the driver, identified only as Safiullah, was a suspect.
"Safiullah is in Kabul at Ministry of Interior facilities," Frans said, adding he had been able to speak with him briefly. "He sounded quite okay. He is one of the witnesses, he is not the only witness. I know his relatives have had access to him."
An Interior Ministry spokesman was not immediately available to comment.
Frans's comments, casting doubt about whether the Taliban were behind the attack, were in contrast to a statement by U.S. Secretary of State Hillary Clinton which directly blamed the Islamist group for what she described as a "despicable act of wanton violence."
On Saturday, the Taliban claimed responsibility for Thursday's killings, saying the medical workers had been carrying bibles in Dari -- one of Afghanistan's two main languages -- and were killed because they were promoting Christianity.
Another Islamist group also said it had carried out the attack.
But Frans said local police had initially raised the possibility of bandits, adding the team's valuables were stolen.
"There are very confusing reports," he said, adding both Afghan and U.S. authorities are investigating the incident.
"If armed opposition claims an attack it is (usually) within hours of it happening. That was not the case this time," Frans said, playing down the Taliban's claim.
The Agency Coordinating Body for Afghan Relief (ACBAR), a network of non-governmental organisations, described the attack as "the worst crime targeting the humanitarian community that has ever taken place in Afghanistan."
"Acts such as this bring not only insufferable grief to the families and friends of the victims but also deprives poor communities of access to basic services," it said in a statement.
The workers, who Frans named as six Americans, two Afghans, a German and a Briton, were members of a 12-strong IAM eye care team that had been working in the remote Badakshan area in the far northeast of the country and neighbouring Nuristan.
U.S. forces withdrew from Nuristan last year after taking heavy losses in years of battle near its Pakistan border.
Clinton had little doubt who was responsible for the killings in Badakshan.
"The Taliban stopped them on a remote road on their journey from Nuristan, led them into a forest, robbed them, and killed them," she said in the statement.
The bodies of the victims will be flown to the United States for a Federal Bureau of Investigation autopsy, Frans said.
IAM has also rejected the Taliban's claim that the group had been proselytising Christianity. Frans said individual members of the team may have been carrying bibles in their own languages but not in Dari.
He said all Afghans working with the IAM were Muslims.
Editing by Paul Tait and Sanjeev Miglani