Russian Human Rights Commissioner Tatiana Moskalkova confirmed on Sunday that Russia and Ukraine carried out a prisoner exchange on Saturday.

Moskalkova said that among those exchanged to Russia, there were four employees of the State Atomic Energy Corporation Rosatom and soldiers.

“Early this morning they landed on the Russian soil,” Moskalkova said in an online post.

Meanwhile, two people were killed and several injured on Sunday in the Ukrainian town of Derhachy in the northeastern Kharkiv region, regional governer Oleh Synyehubov said in a Facebook post.

Russian forces had carried out 66 artillery attacks across several regions the governor said, adding:

“Two people were killed, there are casualties. As you can see, the Russian army continues to ‘fight’ with the civilian population, because it has no victories at the front,” Synyehubov said.

Reuters could not independently verify the details.