French fighter jets have launched their biggest-ever raids in Syria.

Ten jets have targeted Islamic State's stronghold in Raqqa, just two days after I.S. claimed responsibility for the terror attacks in Paris, killing 129 people.

France's Defence Ministry says several sites have been hit, including a command and control point and a jihadi recruitment centre.

Sky's Foreign Affairs Editor, Sam Kiley, says it's not simply an act of retaliation.