Islamic State militants claim to have gained control of the Jahar gas field in central Homs province from the Syrian army.

The militants posted pictures on social media boasting of the capture, which they now consider part of their ‘Caliphate.’ The photos depict an Islamic State (IS, formerly ISIS) flag raised over the field as well as captured Syrian tanks and weapons, says SITE, a jihadist web monitoring service.

IS says they have captured two tanks, seven four-wheel drive cars, and several machine guns after clashes with regime forces.

Last Thursday, the insurgents took control of the Sha’ar gas field, where they killed at least 30 pro-government soldiers, according to the Syrian Observatory for Human Rights (SOHR).

The militants had taken control of the field back in July before the Syrian army temporarily recaptured it.

“So after the [Sha’ar] company and the [positions] surrounding it became part of the land of the caliphate, the soldiers advanced, conquering new areas, and all praise is due to Allah,” the Islamic State said in a message.

The jihadists have been making a killing with revenues from stolen oil fields and refineries seized in Iraq and Syria over the summer and early autumn. US officials and terrorism experts estimated that profits hovered around $2 million a day in September, before the US-led airstrike campaign on IS strongholds, which is thought to have slashed profits by 70 percent, according to the Paris-based International Energy Agency.

However, most of the airstrikes have so far targeted oil and gas fields on Syrian territory rather than Iraq.

READ MORE: Islamic State seeks crisis manager to save ailing oil revenues - report

In cooperation with the US, Canada also dropped bombs on purported IS positions near besieged Kobani on Sunday. Though airstrikes have cut into the IS business model, they have so far done little to halt the Sunni extremists’ offensive.

READ MORE: Canada carries out its first airstrikes against Islamic State