Syria's army announced Thursday the capture of the last town held by the Islamic State group in the country, driving yet another nail into the coffin of its transborder "caliphate".

The latest loss leaves the jihadists clinging on to just a few small pockets of territory in Iraq and Syria, a far cry from the vast stretches they controlled after rampaging across the region in 2014.

Here are the remaining IS holdouts:

- Syria -

After Thursday's loss of the town of Albu Kamal on the border with Iraq, IS is left in control of some two dozen desert villages along the Euphrates river in the surrounding oil-rich Deir Ezzor province that once provided a major source of the group's illicit income.

The jihadists are confronted there both by Syrian regime forces backed up by Russian air power and a coalition of Kurdish and Arab fighters supported by a US-led coalition.

Away from the barren frontier region, IS retains a presence in the Yarmuk refugee camp and the Hajar Aswad district just south of the capital Damascus, where the group is battling other jihadists and pro-regime forces.

In the central region of Homs IS is being squeezed by troops loyal to President Bashar al-Assad and their Russian backers as it struggles to maintain its grip on a few small areas.

To the south in Daraa province on the border with Jordan an affiliated group called Jaish Khaled Bin Walid is mainly battling rebel groups.

- Iraq -

After a brutal campaign that has seen them recapture a string of major cities, Iraqi forces are currently waging a final offensive along their side of the frontier with Syria to wipe out the last remnants of IS territory.

The capture of the key town of Al-Qaim and a nearby border crossing on November 3 left the smaller neighbouring outpost of Rawa and surrounding scraps of desert as all that remains under IS control in Iraq.

The frontier area of Iraq's Anbar province is dominated by a handful of powerful Sunni tribes, some of which have dispatched fighters to battle IS alongside government forces.

The region has been known as a hotbed of jihadist insurgency and smuggling since the US-led invasion of Iraq ousted Saddam Hussein in 2003, long before the arrival of IS in 2014.