US special forces tried but failed recently to free US journalist James Foley and other hostages held by militants in Syria, it's emerged.
The Pentagon says a rescue operation was attempted, focusing on a 'captor network' within ISIL, now known as the Islamic State.
Officials suggest the captives were not present at the time of the raid but that several militants were killed.
A video showing the beheading of James Foley was published by IS on Tuesday, calling for an end to US airstrikes in Iraq.
IS controls swathes of Syria and Iraq but the US and other nations have begun supplying Kurdish Peshmerga forces with weapons to assist their fight against the militants.
Reporter Sarah Williams is in the Kurdistan regional capital Erbil and says the Peshmerga believe this could be a turning point.
IN: "Weapons...
OUT: ...take place."
DUR: 26 seconds
ALT:
Reporter Sarah Williams is in the Kurdistan regional capital Erbil and says the weapons are beginning to arrive at some - but not all - stretches of the front line against IS militants.
IN: "There are...
OUT: ...militants."
DUR: 32 seconds