Pentagon officials continue to play up the “sacrifice” of a pair of US Army Rangers who were killed earlier this week in fighting in eastern Afghanistan. Yet the circumstances surrounding their deaths remain uncertain, with indications they may have been killed by “friendly fire.”

The Rangers were participating in an anti-ISIS raid at the time when they were killed with small arms fire, but officials concede they have no idea who actually shot them, and that they might well have been shot either by other US troops in the area, or by Afghan commandos participating in the raid.

Pentagon spokesman Capt. Jeff Davis says the raid was aimed at killing the leader of ISIS in Afghanistan, and that the military “suspects” they might’ve done so, but aren’t really sure about that either. Some 50 US Army Rangers participated in the attack.

The two slain Rangers were shot almost immediately after they started the attack, and while there was some limited ISIS fire from fortified tunnels during the operation, there seems to be suspicion that the fact that US troops and Afghan commandos approached from opposite directions, and both came in firing, left the Rangers in a crossfire situation.