The Islamic State's brutal murders of American journalists James Foley and Steven Sotloff by a man who spoke with a British accent has drawn more attention to foreign fighters in Syria.
Though it isn't certain both videos were recorded in Syria, the man dubbed "Jihadi John" is probably just one of up to 500 Britons fighting there.
CNN has estimated that up to 11,000 foreigners have travelled to Syria to take up arms agains Bashar Al Assad's government. When Islamic majority countries aren't taken into account, then the vast majority of these come from Russia, unsurprising given its large Muslim population. Substantial numbers of fighters have also come from France, the United Kingdom and Germany - some 700, 500 and 300 respectively. Over 100 fighers have also travelled to Syria from the United States.
This chart shows the estimated number of jihadis in Syria from selected countries in 2014.
You will find more statistics at Statista