NATO authorities have so far found no evidence to support Afghan claims of torture, murder and misconduct by U.S. special forces in a key eastern province, the alliance’s spokesman said on Monday.

“We take all allegations of misconduct seriously and go to great lengths to determine the facts surrounding them,” German general Gunter Katz told reporters. “Over the past few weeks there have been various allegations of Special Forces conducting themselves in an unprofessional manner” in Wardak.

He added that “so far, we could not find evidence that would support these allegations.”

Katz said the International Security Assistance Force will work with the Afghan government to find a solution to civilian concerns but could not comment on the actual allegations against the U.S. forces.