A US soldier with the NATO-led coalition was detained after an incident that resulted in Afghan casualties in southern Afghanistan, officials said Sunday. "A United States service member was detained today in connection with an incident that resulted in Afghan casualties in Kandahar province," NATO said, without giving any other details. An Afghan official confirmed the incident in the Panjwai district of Kandahar. "According to our primary information, 10 to 15 Afghan civilians were killed by the US soldier in the district early Sunday," Kandahar provincial governor's office told DPA. "This is a deeply regrettable incident and we extend our thoughts and concerns to the families involved," the NATO statement said. It also said US forces would investigate the incident with local authorities.