The UN is ready to send experts to investigate the deaths of Ukrainian soldiers in Yelenovka, Russian media reported citing Farhan Haq, the deputy spokesman for the organization's secretary-general, on Saturday. 

Russia claimed on Friday that at least 40 people were killed when Ukraine struck a prison in Yelenovka in the "Donetsk People's Republic."

But Ukraine has denied the Russian accusation, saying Moscow was responsible for the attack and aimed to cover up its treatment of prisoners.

The International Committee of the Red Cross on Friday also said it was aware of reports concerning an attack on a facility where prisoners of war were being held.

"We have requested access to determine the health and condition of all the people present on-site at the time of the attack. We are also in contact with families, taking their requests and inquiries," it said in a statement.