NATO spokesman Birgadier-General Carsten Jacobson told the BBC that the coalition force deployed in Afghanistan was investigating the incident, and sent condolences. He said a combined force of Afghan and NATO troops were in the area when "a tactical situation developed on the ground", though he gave no further details.
He said close air support was called in, and "we`re aware it`s highly likely this caused casualties". In a statement, commander Gen John R Allen said the incident "has my highest personal attention and my commitment to thoroughly investigate it to determine the facts".
He added: "My most sincere and personal heartfelt condolences go out to the families and loved ones of any members of Pakistan Security Forces who may have been killed or injured."