A spokesman for the Kurdish-led Syrian Democratic Forces (SDF), however, denied the claim.

Naim al-Kaood, the head of the security department in Iraq's Anbar province, which borders Syria, told AFP the jihadists were "wanted" by the Iraqi government, while a commander of the Hashed al-Shaabi paramilitary force said they were all Iraqi nationals.

Iraqi forces "were handed by the Syrian Democratic Forces 130 Daesh terrorists wanted by the Iraqi government," Kaood said.

The Hashed commander, who declined to be named, said the jihadists were handed over to authorities including members of military intelligence.

"Other groups will be handed over to Iraq, including families of the jihadists," the commander said.

The Syrian Observatory for Human Rights issued a similar report on Thursday.

But the Britain-based war monitor said that around 150 IS jihadists and family members were handed back to Iraq.

The Observatory said IS family members were taken from Syria to Iraq in trucks of the US-led coalition that has been fighting the jihadists in the two countries.

SDF spokesman Mustefa Bali denied Iraq's claims.

"We deny this information part and parcel," he said.

The Iraqi reports come as SDF forces, backed by coalition air strikes, have trapped IS jihadists in less that half a square kilometre (a fifth of a square mile) in the village of Baghouz, their last redoubt in eastern Syria.

A final offensive to oust diehard jihadists from Baghouz has stalled as SDF forces try to negotiate the release of hundreds of civilians -- mostly wives and children of IS fighters -- who are still inside the village.

On Wednesday, hundreds of people, including women and children, were trucked out of Baghouz.