Backed by air strikes of the US-led coalition, the Kurdish-led Syrian Democratic Forces are battling to expel IS from a few hamlets in the eastern province of Deir Ezzor.
But cornered in a final remote pocket of territory near the Iraqi border, the jihadists are staging a fierce fightback, hiding in tunnels and deploying suicide bombers -- including women.
Listening to Egyptian diva Umm Kulthum, SDF fighters drive along a desert road towards a string of villages retaken in recent weeks from the jihadists.
"The Islamic State has surrendered," reads graffiti scrawled across the wall of a small house at the entrance to the deserted village of Shaafa.
Nearby, a cart once used to sell fruit and vegetables lies abandoned.
The armoured car continues southwards, to where the Kurdish-led SDF is battling to secure the last patch of the village of Baghouz from the jihadists.
The Syrian Observatory for Human Rights this week said the village had been retaken, but SDF commanders on the ground say some IS fighters still remain, and are fighting back hard.
"Two women blew themselves up near our position," an SDF official tells AFP.
"We saw them come towards us dressed in black. They cried 'God is greatest' and then blew themselves up," he says, giving his name as Damat.
- 'Cornered' -
Aram Jaweesh, a commander in the SDF, says five women blew themselves up in various parts of Baghouz on Saturday, killing one SDF member and wounding three others.
IS suicide bombers are usually men, but some women have carried out such operations in Iraq.
From a rooftop, Jaweesh oversees operations, issuing instructions to his fighters in Kurdish through a walkie-talkie that never leaves his side.
A few streets away, armoured cars from the international coalition rumble by.
SDF advances in recent weeks have whittled away at the last pocket of Syrian territory the group controls, and Jaweesh says the noose is tightening around IS.
"They're cornered between the Iraqi border on one side and the SDF on the other," he says.
Late Saturday, four more suicide bombers killed 11 SDF fighters, according to the Britain-based Observatory, while a further 19 jihadists lost their lives in air strikes.
Coalition war planes zip across the skies above Baghouz.
A blast resonates, then a mushroom cloud of smoke rises above its houses.
- Civilian exodus -
On the roof, an SDF fighter points to another spot in the village.
"Look, civilians are coming out," he says.
Thousands of people, mostly relatives of IS fighters, have fled the ever-shrinking IS pocket in recent weeks.
When they reach SDF-held territory, those who are suspected of being fighters are detained for questioning, while relatives are ferried north to Kurdish-run camps.
IS swept across large parts of Syria and Iraq in 2014, declaring a "caliphate" there and ruling it with a brutal version of Islamic law.
It has since lost almost all of it to various offensives.
Earlier this week, the SDF's commander-in-chief told AFP that his forces would have flushed out the last shreds of the quasi-state within a month.
Leaving Baghouz, the armoured car drives into the dark, cold desert, traditional Kurdish songs now blasting from its speakers.
Jaweesh says the battle has yet to be won -- the jihadists may be encircled in a small area, but they are still launching rockets and drones.
"Every time our forces lead an assault, they emerge from tunnels and blow themselves up," he says.