The group consisted of a Dutch woman and her two children as well as another 12-year-old girl, "a humanitarian case," whose mother had agreed to her repatriation following a request from the Dutch government, top Syrian Kurdish foreign affairs official Abdel Karim Omar said.

The four were handed over to a delegation led by The Hague's Syria envoy Emiel de Bont and senior foreign ministry official Dirk Jan Nieuwenhuis.

De Bont said the delegation had "a clear and well-defined mandate to receive in the care of a mission, a small number of Dutch nationals up to now residing in the Roj detention facility", following a Dutch court ruling on the individuals' cases.

"We are here then to serve the rule of law and to do what we can to assist the due legal process," he added.

Since the fall of IS's self-styled "caliphate" in March 2019, Syria's Kurds have repeatedly urged foreign countries to repatriate their nationals held in northeast Syria.

At least 220 children with Dutch nationality remain in Syria or Turkey, 75 percent of whom are under the age of four and were born in the region to parents with Dutch citizenship.

At a press conference in the regional capital Qamishli, Kurdish official Omar reiterated calls for other countries to "meet their responsibilities by repatriating their citizens and cooperating with us on this situation", a major burden for authorities in the de facto autonomous region.

About 75 boys and girls are living with their mothers in Kurdish-run camps in Syria, while a few are also in the jihadist-run northwestern area of Idlib, according to Dutch authorities.

There are some 30 Dutch women and 15 men in Kurdish-run camps.

- Thorny issue -

Anna Sophia Posthumus, spokeswoman for the Netherlands justice and security ministry, said the country did not have a "general policy" of repatriating people from war-torn regions.

She said also there have only been one exception in 2019 with two minors.

"We would prefer a tribunal in the region, have had discussions but its still at a very starting, initial phase," she said.

The question of repatriating Dutch nationals in areas formerly held by IS is a thorny issue in the Netherlands.

Prime Minister Mark Rutte's liberal VVD party has emphasised the security threat posed by such returns, while the centre-left D66 party, a likely potential partner as he seeks to build a coalition, supports bringing back children on humanitarian grounds.

VVD politician Ingrid Michon tweeted that "We do everything that's possible to keep Netherlands safe. Then we should not pick up these IS-goers from Syria. This is about our safety. Stop this."

Far right-wing politician Geert Wilders said it was "unacceptable and unbearable" to repatriate women linked to IS fighters.

"Those terror women have forfeited their right to ever set foot on Dutch soil," he tweeted.