As the UK debates joining a military campaign against the Islamic State, the latest data suggest more than 13,000 foreign fighters have swelled the ranks of the Islamic State.
Above: Abu Luqman, Abu Faariss and Abu Dujana – IS fighters in Syria
In the debate on Friday David Cameron said Britain had to take action to defeat the “poisonous ideology” that had led to young Britons joining the ranks of extremists such as Islamic State.
“The threat of radicalisation is already here. Young people have left our country to go and fight with these extremists,” he said.
Among those that have joined the ranks of the Islamic State group or the extremist al-Nusrah Front are an estimated 3,000 Europeans. Britons make up at least 400 of the fighters, with Mr Cameron telling the UN on Wednesday that 500 jihadis had traveled from the UK.
Data from the Soufan Group, below, shows the estimates of foreign fighters from different countries that have journeyed to fight in Syria.