Fighters of Islamic State extremist group forbidden in Russia and a number of the countries have lost control over 22% of territories which were under their control in Syria and Iraq over the last 14 months. It is stated in the research of IHS research company.

According to the estimates of experts of the company, ISIS has lost 40% of its revenue - mainly from oil sale, BBC Russian service reported.

It has occurred because extremists don't control the Syrian-Turkish border any more.

In comparison with a former assessment of analytical agency, the territory controlled by the so-called Islamic State has decreased by 8%.