According to a leading expert, the Islamic State group, with a fighting force of 10,000 militants, now controls territory as big as the size of United Kingdom and makes 6,00,000 pounds a day.
The IS militants make money by selling oil and ransoming hostages, claimed the expert.
A senior U.S. counter-terrorism official Matthew Olsen said that the Islamic State is an exceptionally dangerous organization that is working in an extremely chaotic part of the world.
Olsen said that the organization now sees itself as the leader of the 'Jihadist movement', reported the Independent.
The Islamic State has spread rapidly across Syria and Iraq due to the failure of the Syrian government to curb the group's activity in their country where it started as a rebellion against President Bashar al-Assad, said the counter-terrorism official.
