(VOVworld) - A US-led air strike mistakenly killed 18 members of a Kurdish and Arab militia backed by Washington south of the Syrian city of Tabqa. The Pentagon said on Thursday that the US-led coalition forces struck the position on Tuesday after another partner in the fight wrongly told them it was occupied by Islamic State militants. The target location was actually a forward Syrian Democratic Forces (SDF) fighting position.  The SDF is fighting in a campaign to encircle and ultimately capture Raqqa city, Islamic State's main base of operations in Syria.

The SDF said its leadership is working with the coalition to investigate the incident and prevent it from happening again.