The Islamic State (Isis) has slashed the wages of its jihadist fighters by half as they begin to feel the pinch of losing ground in the 'caliphate' and coalition airstrikes on oil fields and banks. Daesh (Isis) have announced that the cut will drop a Syrian jihadists monthly earnings to about £140 ($200) from £280 ($400) per month, according to the British-based Syrian Observatory for Human Rights monitoring group.

Foreign fighters are paid double that of Syrian or Iraq combatants and they will now see their monthly income reduced to £280 ($400) per month. Isis territory has been depleted in the last few months thanks to Kurdish Peshmerga offensives in the north of Iraq, Iraqi army offences in Ramadi, and Syrian Army offensives across the breadth of neighbouring Syria.

Coalition forces including the UK, the US, and France have been increasing airstrikes as part of Operation Inherent Resolve. Many of these strikes have been assisting forces opposing Isis, or targeting strategic oil fields that have made Daesh millions of dollars in black market cash.

According to the monitoring group, Isis released a statement saying: "Because of the exceptional circumstances that the Islamic State is passing through, a decision was taken to cut the salaries of the mujahedeen in half. No one will be exempt from this decision no matter his position, but the distribution of food assistance will continue twice a month as usual."

On Saturday 16 January The Pentagon released aerial footage showing millions of dollars of the terrorists' illicit funds being blown hundreds of feet into the air in a targeted strike. The jihadi bank in the Isis stronghold of Mosul, Iraq, was flattened by two 2,000-pound bombs.

Isis has declared a "caliphate" across large swathes of territory in Iraq and Syria, imposing its harsh interpretation of Islamic law. But costs of running the state are high with the implementation of the laws, education and court systems as well as defence.

As with their plundered oil reserves they also make money by selling ancient artefacts stolen from historic sites such as Palmyra and Nimrud. On 20 January it emerged that Isis razed the oldest Christian monastery in Iraq to the ground. The destruction of the 1,400 monastery represents "a battle of savagery against decency," according to US Col. Steve Warren.