The U.S. has begun air strikes on Islamic State targets in Syria for the first time.
Cruise missiles fired from ships in the Gulf are being backed up by bombers and fighter aircraft.
Until now, it's only attacked targets in Iraq.
America's being joined by five Arab states.
Meanwhile - the French Foreign Ministry has confirmed the authenticity of a video showing a French national who's being held by an Islamic State splinter group in Algeria.
I.S. militants had warned they would target France after it launched air strikes against them in Iraq.
Sky's Dominic Waghorn's in New York;
