A convoy of trucks evacuated dozens of people including women and children from the Islamic State group's last Syrian holdout, bringing US-backed forces closer to retaking the last sliver of the "caliphate".

There are also reports from the area that the Kurdish-led SDF forces have now retaken the village of Baghouz. However, there has been no independent confirmation.

The implosion of the so-called IS caliphate, which once spanned swathes of Syria and neighbouring Iraq, has left Western nations grappling with how to handle citizens who left to join IS.

Around 15 trucks carrying men, women and children exited the last patch of IS territory in eastern Syria, according to AFP correspondents.

Women wearing face veils, several children -- including young veiled girls -- as well as men were seen inside the vehicles.

Their exact number and nationalities were not immediately clear.

The convoy passed a position of the Kurdish-led SDF, which are spearheading the battle against the jihadists, after leaving the village of Baghouz, near the Iraqi border.

SDF spokesman Mustefa Bali said the trucks were evacuating a first batch of civilians, but some remained inside.

"After many days of trying, we were able to evacuate the first batch today," he said.

The number of people who quit the holdout would become clear once the convoy arrived at a nearby SDF screening site, he said.

"We don't know if IS fighters are among them, we will know at the screening point," he said.

Backed by air strikes by a US-led coalition, the SDF had trapped IS fighters in less than half a square kilometre (0.2 square miles) of Baghouz.

The SDF had slowed their advance in recent days to protect civilians ahead of a final push to defeat the jihadists.