The Syrian army backed by heavy Russian air strikes seized a string of oil wells in southwest Raqqa province on Saturday.

:: The Syrian army backed by heavy Russian air strikes seized a string of oil wells in southwest Raqqa province on Saturday, as retreating ISIS militants battle to defend their remaining territory in the country.

State-owned Ikhbariyah television quoted a military source as saying the army had taken control of Wahab, al Fahd, Dbaysan, al-Qseer, Abu al Qatat and Abu Qatash oil fields and several other villages in the desert area that lies in the southwest of Raqqa province.

The seized oil fields lie south of the town of Rasafa and its oil wells, which the army took last month from the militants in their first major territorial gains inside the province.

The army and Iranian-backed militias have in the last few months been advancing east of Aleppo city and seizing swathes of territory west of the Euphrates River that militants have pulled out of to defend their de facto capital of Raqqa, where they are now battling US-backed troops inside the city.

The latest gains tighten the army’s grip on a bulge of territory stretching from eastern Hama province to eastern Homs and the edge of Raqqa and Deir Zor provinces, the Syrian Observatory for Human Rights war monitor said.

The monitor said the Russian air force intensified its strikes on several targets and towns held by the militants in the area including Uqairbat, a target of Russian cruise missiles fired from warships in the Mediterranean at the end of May.

The army’s next goal is to retake the town of Sukhna, a gateway to the eastern province of Deir Zor that borders Iraq and likely to be the militants’ last major bastion in Syria if Raqqa falls.