Iraq and Syria: How many foreign fighters are fighting for Isil?

It is estimated that over 20,000 foreign fighters have travelled to Iraq and Syria since fighting broke out in 2011.

While there are no confirmed figures for the official tally, experts predict that many are still fighting in the conflict zone – while a significant proportion have travelled home.

Already more have travelled to the region than the total who traveled to Afghanistan during its ten-year war.

As well as the Islamic State (also known as Isil and Isis), which is attracting increasing numbers to its cause, there are several other factions fighting in Iraq and Syria.