London, April 28: A combination of airstrikes on Islamic State (IS)-controlled oil fields, recapture of held territory and destruction of cash storage sites containing up to $800 million, may have financially weakened the terror group, latest military figures showed.
Britain's defence ministry officials claimed they saw signs that the IS is increasingly resorting to arbitrary fines, extortion and gangsterism to make up a shortfall in income, The Guardian reported on Thursday, April 28.
Speaking about the campaign for the first time, Air Vice Marshal Edward Stringer, senior British civil servant in charge of undermining IS finances, said: "What we are now seeing is that they are running short of cash and they are looking for more imaginative ways to do things."
The gangsterism was tarnishing the IS brand, he claimed.
In Baghdad, the deputy US commander for operations and intelligence, Major Genreal Peter E Gersten, said up to $800 million held in IS storage facilities were blown up by coalition airstrikes.
The number of foreign fighters joining the extremists was down by 8 percent, he claimed.
The defence ministry is reluctant to give an estimate of IS's annual income.
However, retrieved spreadsheets showed that its natural resource revenues in the six months to February 2015 amounted to $290 million, about 70 percent of which came from the giant al-Omar oilfield in Deir ez-Zor, previously run by Royal Dutch Shell.
Since then, there were 1,216 strikes on oil infrastructure targets and tankers, reducing production by 25 percent and cutting revenue by 10 percent.
Aside from oil production, IS's tax base is eroding as it cedes territory. Last year, the group lost 14 percent of its land, and a further 8 percent in the past three months. The population under IS control has declined from 9 million to 6 million.
The squeeze has led to pay cuts for foreign fighters. The Pentagon claimed this week that the number of such individuals entering IS territory had plummeted by 90 percent in the past year.