A US soldier has killed 16 Afghan civilians, including nine children, after entering their homes in Kandahar. Sky sources said the Afghan victims also included women and elderly men. Minister of Border and Tribal Affairs Asadullah Khalid, who is investigating the incident, said the soldier entered three homes, killing 11 people in the first one. The Nato-led International Security Assistance Force (Isaf) coalition confirmed the incident but did not release the number of killed or injured. Sky defence reporter Mark Stone said: "Details are still sketchy and various death tolls have emerged. "It appears to be an isolated incident and the soldier is believed to have been a staff sergeant." Isaf Deputy Commander Lt Gen Adrian Bradshaw said: "I wish to convey my profound regrets and dismay at the actions apparently taken by one coalition member in Kandahar province. "I cannot explain the motivation behind such callous acts, but they were in no way part of authorised ISAF military activity." According to the Panjwai district governor office, seven people died and up to 17 injured were injured in the rampage. The injured have been treated for their wounds at Nato medical facilities. Protests were held over the Koran-burning incident The US embassy in Kabul attempted to quell expected Afghan unrest by also issuing an apology. It said: "We deplore any attack by a member of the US armed forces against innocent civilians, and denounce all violence against civilians. "We assure the people of Afghanistan that the individual or individuals responsible for this act will be identified and brought to justice." The diplomatic response comes after weeks of tense relations between US forces and their Afghan hosts following the burning of Korans and other religious materials at an American base. Although US officials apologised and said the burning was an accident, the incident sparked violent protests and attacks. Britain also pulled out civilian advisers from buildings in Kabul as protests spread. Six American soldiers have been killed in attacks by their Afghan colleagues since the Koran burnings came to light.