In 60 seconds: What does Islamic State want?

The US and Arab allies have launched strikes against Islamic State (IS) militants in Syria.

The Pentagon said warplanes, drones and Tomahawk missiles were used in the attacks, which targeted several areas including IS stronghold Raqqa.

The move follows US air strikes against IS targets in Iraq.

The BBC explains who the jihadists are - and what they want - in 60 seconds.

Video produced by Michael Hirst