Iraqi armed forces said on Saturday they had started an offensive to dislodge ISIS militants from an area on the border with Syria by attacking a desert terrorist outpost.

The offensive in Anbar province’s Akashat region south of the Euphrates is meant to pave the way for the seizure of militant-held towns in the river’s valley, including the border post of al-Qaim, military statements said.

Akashat, which has natural gas reserves and was once a major source of phosphate production, lies some 100 kilometers south of al-Qaim.

Al-Qaim and the Euphrates towns of Rawa and Anna downstream form just one of two enclaves still held by ISIS in Iraq after a string of battlefield defeats this year.

Iraqi commanders estimate there are no more than 300 civilian families left in Akashat and that ISIS still has more than 1,500 armed members in its al-Qaim enclave.

The militants also control a second enclave west of Kirkuk centered on the town of Hawija.