KABUL, Jan. 25 (Xinhua) -- The Afghan government has launched an investigation to probe an airstrike that left civilians dead in restive southern Helmand province, the Ministry of Defense said on Friday.

"During an Afghan National Army cleanup operation against Taliban in Sangin district, Helmand province within past three days, there has been reports that Afghan civilians were accidentally killed," the ministry said in a statement.

Without giving the exact number of civilian fatalities, the statement said that the ministry has appointed an incident assessment team to investigate thoroughly the incident and share the findings with the government and people of Afghanistan.

At least 13 civilians were killed following the raid which occurred on Wednesday night and it was not clear whether the strike was launched by Afghan Air Force or NATO-led coalition forces, according to local media reports.