According to a U.N. report, an estimated 15,000 fighters from around the world have left their homes to join extremist groups operating in Iraq and Syria. It adds that actual numbers could be even higher...
The report, which was submitted to the U.N. Security Council by a panel that monitors al Qaeda and the Taliban, states that foreign fighters are joining the Islamic State and other extremist groups on "an unprecedented scale." They are coming mainly from the Middle East, Western Europe and North Africa, although there are also some Asians and a smaller number of Americans.