A dozen Ukrainian children who were in Russian-occupied territory have been returned to parts of the country controlled by Kyiv, a regional official said Friday.

Kyiv has accused Moscow of abducting almost 20,000 children from parts of the east and south of Ukraine, while many more have found themselves living under Russian control after Moscow's troops invaded in February 2022.

"Twelve children were returned to territory controlled by Ukraine," Oleksandr Prokudin, the Ukrainian governor of the southern Kherson region, said Friday in a post on Telegram.

Three boys and nine girls, aged between two and 17, were transferred from parts of the Kherson region that are under the control of Russian forces to the Ukrainian-held side, he added.

One of the children had been "deprived of parental care".

Kyiv has made returning the children to Ukrainian-controlled territory one of its top diplomatic priorities.

Russia has said it moved some Ukrainian children away from their houses or orphanages that were close to the fighting for their own protection.

But Moscow has also been accused of effectively abducting some of them, trying to scrub their Ukrainian identity and putting them up for permanent adoption with Russian families.

The International Criminal Court has issued an arrest warrant for Russian President Vladimir Putin and his children's rights commissioner, Maria Lvova-Belova, over the allegations.